1
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Rolfe M, Hayes S, Smith M, Owen M, Spruth M, McCarthy C, Forkan A, Banerjee A, Hocking RK. An AI based smart-phone system for asbestos identification. J Hazard Mater 2024; 463:132853. [PMID: 37918071 DOI: 10.1016/j.jhazmat.2023.132853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/13/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023]
Abstract
Asbestos identification is a complex environmental and economic challenge. Typical commercial identification of asbestos involves sending samples to a laboratory where someone learned in the field uses light microscopy and specialized mounting to identify the morphologically distinct signatures of Asbestos. In this work we investigate the use of a portable (30x) microscope which works with a smart phone camera to develop an image recognition system. 7328 images from over 1000 distinct samples of cement sheet from Melbourne, Australia were used to train a phone-based image recognition system for Asbestos identification. Three common CNN's were tested ResNet101, InceptionV3 and VGG_16 with ResNet101 achieving the best result. The distinctiveness of Asbestos was found to be identified correctly 90% of the time using a phone-based system and no specialized mounting. The image recognition system was trained with ResNet101 a convolutional neural network deep learning model which weights layers with a residual function. Resulting in an accuracy of 98.46% and loss of 3.8% ResNet101 was found to produce a more accurate model for this use-case than other deep learning neural networks.
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Affiliation(s)
- Michael Rolfe
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia
| | - Samantha Hayes
- Agon Environmental Pty, Ltd 63-85 Turner Street, Port Melbourne, VIC 3207, Australia
| | - Meaghan Smith
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia
| | - Matthew Owen
- Identifibre Pty Ltd., 67 Atherton Road, Oakleigh, VIC 3166, Australia
| | - Michael Spruth
- Agon Environmental Pty, Ltd 63-85 Turner Street, Port Melbourne, VIC 3207, Australia
| | - Chris McCarthy
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia
| | - Abdur Forkan
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia
| | - Abhik Banerjee
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology and Department of Computing Technologies, School of Science, Computing and Engineering Technologies, Swinburne University of Technology Melbourne, VIC 3122, Australia.
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2
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Kruczała K, Neubert S, Dhaka K, Mitoraj D, Jánošíková P, Adler C, Krivtsov I, Patzsch J, Bloh J, Biskupek J, Kaiser U, Hocking RK, Caspary Toroker M, Beranek R. Enhancing Photocatalysis: Understanding the Mechanistic Diversity in Photocatalysts Modified with Single-Atom Catalytic Sites. Adv Sci (Weinh) 2023; 10:e2303571. [PMID: 37888857 PMCID: PMC10724417 DOI: 10.1002/advs.202303571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/16/2023] [Indexed: 10/28/2023]
Abstract
Surface modification of heterogeneous photocatalysts with single-atom catalysts (SACs) is an attractive approach for achieving enhanced photocatalytic performance. However, there is limited knowledge of the mechanism of photocatalytic enhancement in SAC-modified photocatalysts, which makes the rational design of high-performance SAC-based photocatalysts challenging. Herein, a series of photocatalysts for the aerobic degradation of pollutants based on anatase TiO2 modified with various low-cost, non-noble SACs (vanadate, Cu, and Fe ions) is reported. The most active SAC-modified photocatalysts outperform TiO2 modified with the corresponding metal oxide nanoparticles and state-of-the-art benchmark photocatalysts such as platinized TiO2 and commercial P25 powders. A combination of in situ electron paramagnetic resonance spectroscopy and theoretical calculations reveal that the best-performing photocatalysts modified with Cu(II) and vanadate SACs exhibit significant differences in the mechanism of activity enhancement, particularly with respect to the rate of oxygen reduction. The superior performance of vanadate SAC-modified TiO2 is found to be related to the shallow character of the SAC-induced intragap states, which allows for both the effective extraction of photogenerated electrons and fast catalytic turnover in the reduction of dioxygen, which translates directly into diminished recombination. These results provide essential guidelines for developing efficient SAC-based photocatalysts.
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Affiliation(s)
- Krzysztof Kruczała
- Faculty of ChemistryJagiellonian University in KrakówGronostajowa 2/C1‐21Krakow30–387Poland
| | - Susann Neubert
- Faculty of Chemistry and BiochemistryRuhr University BochumUniversitätsstr. 15044780BochumGermany
| | - Kapil Dhaka
- Department of Materials Science and EngineeringTechnion – Israel Institute of TechnologyHaifa3200003Israel
| | - Dariusz Mitoraj
- Institute of ElectrochemistryUlm UniversityAlbert‐Einstein‐Allee 4789069UlmGermany
| | - Petra Jánošíková
- Faculty of Chemistry and BiochemistryRuhr University BochumUniversitätsstr. 15044780BochumGermany
| | - Christiane Adler
- Institute of ElectrochemistryUlm UniversityAlbert‐Einstein‐Allee 4789069UlmGermany
| | - Igor Krivtsov
- Institute of ElectrochemistryUlm UniversityAlbert‐Einstein‐Allee 4789069UlmGermany
- Department of Chemical and Environmental EngineeringUniversity of OviedoOviedo33006Spain
| | - Julia Patzsch
- Chemical Technology GroupDECHEMA Research InstituteTheodor‐Heuss‐Allee 2560486Frankfurt am MainGermany
| | - Jonathan Bloh
- Chemical Technology GroupDECHEMA Research InstituteTheodor‐Heuss‐Allee 2560486Frankfurt am MainGermany
| | - Johannes Biskupek
- Central Facility of Electron MicroscopyElectron Microscopy Group of Material ScienceUniversity of UlmD‐89081UlmGermany
| | - Ute Kaiser
- Central Facility of Electron MicroscopyElectron Microscopy Group of Material ScienceUniversity of UlmD‐89081UlmGermany
| | - Rosalie K. Hocking
- Department of Chemistry and BiotechnologyARC Training Centre for Surface Engineering for Advanced Material SEAMSwinburne University of TechnologyHawthornVIC3122Australia
| | - Maytal Caspary Toroker
- Department of Materials Science and EngineeringTechnion – Israel Institute of TechnologyHaifa3200003Israel
- The Nancy and Stephen Grand Technion Energy ProgramTechnion – Israel Institute of TechnologyHaifa3200003Israel
| | - Radim Beranek
- Institute of ElectrochemistryUlm UniversityAlbert‐Einstein‐Allee 4789069UlmGermany
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3
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Dang MN, Singh S, Navarro-Devia JH, King HJ, Hocking RK, Wade SA, Stephens G, Papageorgiou A, Wang J. An Investigation into the Surface Integrity of Micro-Machined High-Speed Steel and Tungsten Carbide Cutting Tools. Micromachines (Basel) 2023; 14:1970. [PMID: 37893407 PMCID: PMC10608892 DOI: 10.3390/mi14101970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/15/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
The performance and lifespan of cutting tools are significantly influenced by their surface quality. The present report highlights recent advances in enhancing the surface characteristics of tungsten carbide and high-speed steel cutting tools using a novel micro-machining technique for polishing and edge-honing. Notably, the main aim was to reduce the surface roughness while maintaining the hardness of the materials at an optimal level. By conducting a thorough analysis of surfaces obtained using different techniques, it was found that the micro-machining method effectively decreased the surface roughness of the cutting tools the most effectively out of the techniques investigated. Significantly, the surface roughness was reduced from an initial measurement of 400 nm to an impressive value of 60 nm. No significant change in hardness was observed, which guarantees the maintenance of the mechanical properties of the cutting tools. This analysis enhances the comprehension of surface enhancement methodologies for cutting tools through the presentation of these findings. The observed decrease in surface roughness, along with the consistent hardness, exhibits potential for improving tool performance. These enhancements possess the capacity to optimise manufacturing processes, increase tool reliability, and minimise waste generation.
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Affiliation(s)
- Minh Nhat Dang
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
| | - Surinder Singh
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
| | | | - Hannah J. King
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
| | - Rosalie K. Hocking
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
| | - Scott A. Wade
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
| | - Guy Stephens
- Sutton Tools, 378 Settlement Rd, Thomastown, VIC 3074, Australia
| | | | - James Wang
- The Australian Research Council (ARC) Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia
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4
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Garibello CF, Simonov AN, Chang SLY, Johannessen B, Malherbe F, Eldridge DS, Hocking RK. Tuning Catalyst Selectivity for Ammonia vs Hydrogen: An Investigation into the Coprecipitation of Mo and Fe Sulfides. Inorg Chem 2023. [PMID: 37279492 DOI: 10.1021/acs.inorgchem.3c00322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Iron sulfides are key materials in metalloprotein catalysis. One interesting aspect of iron sulfides in biology is the incorporation of secondary metals, for example, Mo, in nitrogenase. These secondary metals may provide vital clues as to how these enzymes first emerged in nature. In this work, we examined the materials resulting from the coprecipitation of molybdenum with iron sulfides using X-ray absorption spectroscopy (XAS). The materials were tested as catalysts, and direct reductants using nitrite (NO2-) and protons (H+) as test substrates. It was found that Mo will coprecipitate with iron as sulfides, however, in distinct ways depending on the stoichiometric ratios of Mo, Fe, and HS-. It was observed that the selectivity of reduction products depends on the amount of molybdenum, with the presence of approximately at 10% Mo optimizing ammonium/ammonia (NH4+/NH3) production from NO2- and minimizing competitive hydrogen (H2) formation from protons (H+) with a secondary reductant.
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Affiliation(s)
- C Felipe Garibello
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
| | - Alexandr N Simonov
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Shery L Y Chang
- School of Materials Science and Engineering and Electron Microscope Unit, Mark Wainwright Analytical Centre and University of New South Wales Sydney, Sydney, NSW 2052, Australia
| | - Bernt Johannessen
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation (ANSTO), Clayton, Victoria 3168, Australia
| | - François Malherbe
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
| | - Daniel S Eldridge
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
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5
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Tran-Phu T, Chatti M, Leverett J, Nguyen TKA, Simondson D, Hoogeveen DA, Kiy A, Duong T, Johannessen B, Meilak J, Kluth P, Amal R, Simonov AN, Hocking RK, Daiyan R, Tricoli A. Understanding the Role of (W, Mo, Sb) Dopants in the Catalyst Evolution and Activity Enhancement of Co 3 O 4 during Water Electrolysis via In Situ Spectroelectrochemical Techniques. Small 2023:e2208074. [PMID: 36932896 DOI: 10.1002/smll.202208074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Unlocking the potential of the hydrogen economy is dependent on achieving green hydrogen (H2 ) production at competitive costs. Engineering highly active and durable catalysts for both oxygen and hydrogen evolution reactions (OER and HER) from earth-abundant elements is key to decreasing costs of electrolysis, a carbon-free route for H2 production. Here, a scalable strategy to prepare doped cobalt oxide (Co3 O4 ) electrocatalysts with ultralow loading, disclosing the role of tungsten (W), molybdenum (Mo), and antimony (Sb) dopants in enhancing OER/HER activity in alkaline conditions, is reported. In situ Raman and X-ray absorption spectroscopies, and electrochemical measurements demonstrate that the dopants do not alter the reaction mechanisms but increase the bulk conductivity and density of redox active sites. As a result, the W-doped Co3 O4 electrode requires ≈390 and ≈560 mV overpotentials to reach ±10 and ±100 mA cm-2 for OER and HER, respectively, over long-term electrolysis. Furthermore, optimal Mo-doping leads to the highest OER and HER activities of 8524 and 634 A g-1 at overpotentials of 0.67 and 0.45 V, respectively. These novel insights provide directions for the effective engineering of Co3 O4 as a low-cost material for green hydrogen electrocatalysis at large scales.
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Affiliation(s)
- Thanh Tran-Phu
- Nanotechnology Research Laboratory, Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW, 2006, Australia
| | - Manjunath Chatti
- School of Chemistry, Monash University, Monash, Victoria, 3800, Australia
| | - Joshua Leverett
- Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Thi Kim Anh Nguyen
- Nanotechnology Research Laboratory, Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW, 2006, Australia
| | - Darcy Simondson
- School of Chemistry, Monash University, Monash, Victoria, 3800, Australia
| | - Dijon A Hoogeveen
- School of Chemistry, Monash University, Monash, Victoria, 3800, Australia
| | - Alexander Kiy
- Department of Materials Physics, Research School of Physics, The Australian National University, Canberra, ACT, 2601, Australia
| | - The Duong
- School of Engineering, The Australian National University, Canberra, ACT, 2601, Australia
| | | | - Jaydon Meilak
- Department of Chemistry and Biotechnology, Swinburne University, Hawthorn, Victoria, 3166, Australia
| | - Patrick Kluth
- Department of Materials Physics, Research School of Physics, The Australian National University, Canberra, ACT, 2601, Australia
| | - Rose Amal
- Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Alexandr N Simonov
- School of Chemistry, Monash University, Monash, Victoria, 3800, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Swinburne University, Hawthorn, Victoria, 3166, Australia
| | - Rahman Daiyan
- Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Antonio Tricoli
- Nanotechnology Research Laboratory, Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW, 2006, Australia
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6
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Dastafkan K, Shen X, Hocking RK, Meyer Q, Zhao C. Monometallic interphasic synergy via nano-hetero-interfacing for hydrogen evolution in alkaline electrolytes. Nat Commun 2023; 14:547. [PMID: 36725848 PMCID: PMC9892594 DOI: 10.1038/s41467-023-36100-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/16/2023] [Indexed: 02/03/2023] Open
Abstract
Electrocatalytic synergy is a functional yet underrated concept in electrocatalysis. Often, it materializes as intermetallic interaction between different metals. We demonstrate interphasic synergy in monometallic structures is as much effective. An interphasic synergy between Ni(OH)2 and Ni-N/Ni-C phases is reported for alkaline hydrogen evolution reaction that lowers the energy barriers for hydrogen adsorption-desorption and facilitates that of hydroxyl intermediates. This makes ready-to-serve Ni active sites and allocates a large amount of Ni d-states at Fermi level to promote charge redistribution from Ni(OH)2 to Ni-N/Ni-C and the co-adsorption of Hads and OHads intermediates on Ni-N/Ni-C moieties. As a result, a Ni(OH)2@Ni-N/Ni-C hetero-hierarchical nanostructure is developed, lowering the overpotentials to deliver -10 and -100 mA cm-2 in alkaline media by 102 and 113 mV, respectively, compared to monophasic Ni(OH)2 catalyst. This study unveils the interphasic synergy as an effective strategy to design monometallic electrocatalysts for water splitting and other energy applications.
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Affiliation(s)
- Kamran Dastafkan
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
| | - Xiangjian Shen
- grid.207374.50000 0001 2189 3846Engineering Research Center of Advanced Functional Material Manufacturing of Ministry of Education, Zhengzhou University, Zhengzhou, 450001 China
| | - Rosalie K. Hocking
- grid.1027.40000 0004 0409 2862Department of Chemistry and Biotechnology, Centre for Translational Atomaterials and ARC Training Centre for Surface Engineering for Advanced Material SEAM, Swinburne University of Technology, Hawthorn, VIC 3122 Australia
| | - Quentin Meyer
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
| | - Chuan Zhao
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
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7
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Simondson D, Chatti M, Gardiner JL, Kerr BV, Hoogeveen DA, Cherepanov PV, Kuschnerus IC, Nguyen TD, Johannessen B, Chang SLY, MacFarlane DR, Hocking RK, Simonov AN. Mixed Silver–Bismuth Oxides: A Robust Oxygen Evolution Catalyst Operating at Low pH and Elevated Temperatures. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Darcy Simondson
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | - Manjunath Chatti
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | - James L. Gardiner
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | - Brittany V. Kerr
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn 3122, Victoria, Australia
| | - Dijon A. Hoogeveen
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | | | - Inga C. Kuschnerus
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney 2052, Australia
- School of Materials Science and Engineering, University of New South Wales, Sydney 2052, Australia
| | - Tam D. Nguyen
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | | | - Shery L. Y. Chang
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney 2052, Australia
- School of Materials Science and Engineering, University of New South Wales, Sydney 2052, Australia
| | | | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn 3122, Victoria, Australia
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8
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Garibello CF, Simonov AN, Eldridge DS, Malherbe F, Hocking RK. Redox Properties of Iron Sulfides: Direct
versus
Catalytic Reduction and Implications for Catalyst Design. ChemCatChem 2022. [DOI: 10.1002/cctc.202200617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- C. Felipe Garibello
- Department of Chemistry and Biotechnology School of Science Computing and Engineering Technologies Swinburne University of Technology Victoria 3122 Australia
| | - Alexandr N. Simonov
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science Monash University Victoria 3800 Australia
| | - Daniel S. Eldridge
- Department of Chemistry and Biotechnology School of Science Computing and Engineering Technologies Swinburne University of Technology Victoria 3122 Australia
| | - Francois Malherbe
- Department of Chemistry and Biotechnology School of Science Computing and Engineering Technologies Swinburne University of Technology Victoria 3122 Australia
| | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology School of Science Computing and Engineering Technologies Swinburne University of Technology Victoria 3122 Australia
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9
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Du HL, Chatti M, Kerr B, Nguyen CK, Tran-Phu T, Hoogeveen DA, Cherepanov PV, Chesman ASR, Johannessen B, Tricoli A, Hocking RK, MacFarlane DR, Simonov AN. Durable electrooxidation of acidic water catalysed by a cobalt‐bismuth‐based oxide composite: an unexpected role of the F‐doped SnO2 substrate. ChemCatChem 2022. [DOI: 10.1002/cctc.202200013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Brittany Kerr
- Swinburne University of Technology Faculty of Science, Engineering and Technology AUSTRALIA
| | | | - Thanh Tran-Phu
- Australian National University Research School of Chemistry AUSTRALIA
| | | | | | | | | | | | - Rosalie K. Hocking
- Swinburne University of Technology - Hawthorn Campus: Swinburne University of Technology Faculty of Science, Engineering and Technology AUSTRALIA
| | | | - Alexandr Nikolaevich Simonov
- Monash University School of Chemistry and the ARC Centre of Excellence for Electromaterials Science Wellington Road 3800 Clayton AUSTRALIA
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10
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Orr R, Hocking RK, Pattison A, Nelson PN. Extraction of metals from mildly acidic tropical soils: Interactions between chelating ligand, pH and soil type. Chemosphere 2020; 248:126060. [PMID: 32032879 DOI: 10.1016/j.chemosphere.2020.126060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/10/2020] [Accepted: 01/28/2020] [Indexed: 06/10/2023]
Abstract
Naturally occurring and synthetic chelating ligands can act as suppressants for fungal pathogens, nematodes and weeds, based on their ability to alter micronutrient bioavailability in soil, particularly iron. Chelators are also used as detergents, for remediation of heavy metal contamination and for supplying metals as fertiliser. The aim of this work was to test the ability of chelators to solubilise metals, in particular iron, in tropical soils over an environmentally relevant pH range. Six topsoils from farms in North Queensland, Australia were adjusted to pH 5, 6 and 7 and then extracted with CaCl2, EDTA, DTPA, EDDHA and mimosine. The extracts were analysed for concentrations of aluminium, copper, iron, magnesium, manganese, potassium, strontium and zinc. EDDHA solubilised iron effectively under all of the conditions tested, indicating its likely suitability for pest suppression. The concentration of aluminium in EDDHA extracts was positively correlated with pH, and at pH 7 the concentration of aluminium was far greater than that of iron. An increase in the mobility of aluminium from EDDHA application to soil may lead to aluminium toxicity in plants, which should be considered further in any practical application of EDDHA. Mimosine, which is also a strong chelator, was a poor extractor of all metals, possibly due to adsorption to the soil.
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Affiliation(s)
- Ryan Orr
- James Cook University, College of Science and Engineering, Cairns, QLD, 4878, Australia.
| | - Rosalie K Hocking
- Swinburne University of Technology, Faculty of Science, Engineering and Technology, Hawthorn, VIC, 3122, Australia; James Cook University, College of Science and Engineering, Townsville, QLD, 4814, Australia
| | - Anthony Pattison
- Queensland Department of Agriculture and Fisheries, South Johnstone, QLD, 4859, Australia
| | - Paul N Nelson
- James Cook University, College of Science and Engineering, Cairns, QLD, 4878, Australia
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11
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Li Y, Tan X, Hocking RK, Bo X, Ren H, Johannessen B, Smith SC, Zhao C. Implanting Ni-O-VOx sites into Cu-doped Ni for low-overpotential alkaline hydrogen evolution. Nat Commun 2020; 11:2720. [PMID: 32483179 PMCID: PMC7264301 DOI: 10.1038/s41467-020-16554-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/06/2020] [Indexed: 11/25/2022] Open
Abstract
Nickel-based catalysts are most commonly used in industrial alkaline water electrolysis. However, it remains a great challenge to address the sluggish reaction kinetics and severe deactivation problems of hydrogen evolution reaction (HER). Here, we show a Cu-doped Ni catalyst implanted with Ni-O-VOx sites (Ni(Cu)VOx) for alkaline HER. The optimal Ni(Cu)VOx electrode exhibits a near-zero onset overpotential and low overpotential of 21 mV to deliver –10 mA cm−2, which is comparable to benchmark Pt/C catalyst. Evidence for the formation of Ni-O-VOx sites in Ni(Cu)VOx is established by systematic X-ray absorption spectroscopy studies. The VOx can cause a substantial dampening of Ni lattice and create an enlarged electrochemically active surface area. First-principles calculations support that the Ni-O-VOx sites are superactive and can promote the charge redistribution from Ni to VOx, which greatly weakens the H-adsorption and H2 release free energy over Ni. This endows the Ni(Cu)VOx electrode high HER activity and long-term durability. Producing H2 from water using electricity and earth-abundant elements is necessary for worldwide renewable fuel production, yet most electrocatalysts have sluggish activities or poor stabilities. Here, authors show vanadium oxide modified copper-doped nickel to enable active and durable H2 evolution.
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Affiliation(s)
- Yibing Li
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Xin Tan
- Integrated Materials Design Laboratory, Department of Applied Mathematics, Research School of Physics, The Australian National University, Canberra, ATC, 2601, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Centre for Translational Atomaterials and ARC Training Centre for Surface Engineering for Advanced Material SEAM, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Xin Bo
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Hangjuan Ren
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Bernt Johannessen
- ANSTO Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168, Australia
| | - Sean C Smith
- Integrated Materials Design Laboratory, Department of Applied Mathematics, Research School of Physics, The Australian National University, Canberra, ATC, 2601, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia.
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12
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Suryanto BHR, Wang Y, Hocking RK, Adamson W, Zhao C. Overall electrochemical splitting of water at the heterogeneous interface of nickel and iron oxide. Nat Commun 2019; 10:5599. [PMID: 31811129 PMCID: PMC6898202 DOI: 10.1038/s41467-019-13415-8] [Citation(s) in RCA: 202] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/07/2019] [Indexed: 12/17/2022] Open
Abstract
Efficient generation of hydrogen from water-splitting is an underpinning chemistry to realize the hydrogen economy. Low cost, transition metals such as nickel and iron-based oxides/hydroxides have been regarded as promising catalysts for the oxygen evolution reaction in alkaline media with overpotentials as low as ~200 mV to achieve 10 mA cm-2, however, they are generally unsuitable for the hydrogen evolution reaction. Herein, we show a Janus nanoparticle catalyst with a nickel-iron oxide interface and multi-site functionality for a highly efficient hydrogen evolution reaction with a comparable performance to the benchmark platinum on carbon catalyst. Density functional theory calculations reveal that the hydrogen evolution reaction catalytic activity of the nanoparticle is induced by the strong electronic coupling effect between the iron oxide and the nickel at the interface. Remarkably, the catalyst also exhibits extraordinary oxygen evolution reaction activity, enabling an active and stable bi-functional catalyst for whole cell water-splitting with, to the best of our knowledge, the highest energy efficiency (83.7%) reported to date.
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Affiliation(s)
- Bryan H R Suryanto
- School of Chemistry, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Yun Wang
- Centre for Clean Environment and Energy, School of Environment and Science, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Melbourne, VIC, 3122, Australia
| | - William Adamson
- School of Chemistry, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Kensington, NSW, 2052, Australia.
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13
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Zhuang L, Ge L, Liu H, Jiang Z, Jia Y, Li Z, Yang D, Hocking RK, Li M, Zhang L, Wang X, Yao X, Zhu Z. A Surfactant‐Free and Scalable General Strategy for Synthesizing Ultrathin Two‐Dimensional Metal–Organic Framework Nanosheets for the Oxygen Evolution Reaction. Angew Chem Int Ed Engl 2019; 58:13565-13572. [DOI: 10.1002/anie.201907600] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Linzhou Zhuang
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Lei Ge
- Centre for Future Materials University of Southern Queensland Springfield 4300 Australia
| | - Hongli Liu
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province Institute of Marine Biobased Materials School of Environmental Science and Engineering Qingdao University Shandong 266071 P. R. China
| | - Zongrui Jiang
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Yi Jia
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Zhiheng Li
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Dongjiang Yang
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province Institute of Marine Biobased Materials School of Environmental Science and Engineering Qingdao University Shandong 266071 P. R. China
| | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology Faculty of Science, Engineering and Technology Swinburne University of Technology Hawthorn, Melbourne Victoria 3122 Australia
| | - Mengran Li
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Longzhou Zhang
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Xin Wang
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Xiangdong Yao
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Zhonghua Zhu
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
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14
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Zhuang L, Ge L, Liu H, Jiang Z, Jia Y, Li Z, Yang D, Hocking RK, Li M, Zhang L, Wang X, Yao X, Zhu Z. A Surfactant‐Free and Scalable General Strategy for Synthesizing Ultrathin Two‐Dimensional Metal–Organic Framework Nanosheets for the Oxygen Evolution Reaction. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907600] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Linzhou Zhuang
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Lei Ge
- Centre for Future Materials University of Southern Queensland Springfield 4300 Australia
| | - Hongli Liu
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province Institute of Marine Biobased Materials School of Environmental Science and Engineering Qingdao University Shandong 266071 P. R. China
| | - Zongrui Jiang
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Yi Jia
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Zhiheng Li
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Dongjiang Yang
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province Institute of Marine Biobased Materials School of Environmental Science and Engineering Qingdao University Shandong 266071 P. R. China
| | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology Faculty of Science, Engineering and Technology Swinburne University of Technology Hawthorn, Melbourne Victoria 3122 Australia
| | - Mengran Li
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
| | - Longzhou Zhang
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Xin Wang
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Xiangdong Yao
- School of Environment and Sciences Queensland Micro-Griffith University Nathan Campus 4111 Nathan Australia
| | - Zhonghua Zhu
- School of Chemical Engineering The University of Queensland Brisbane 4072 Australia
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15
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Chatti M, Gardiner JL, Fournier M, Johannessen B, Williams T, Gengenbach TR, Pai N, Nguyen C, MacFarlane DR, Hocking RK, Simonov AN. Intrinsically stable in situ generated electrocatalyst for long-term oxidation of acidic water at up to 80 °C. Nat Catal 2019. [DOI: 10.1038/s41929-019-0277-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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16
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Tesch MF, Bonke SA, Jones TE, Shaker MN, Xiao J, Skorupska K, Mom R, Melder J, Kurz P, Knop‐Gericke A, Schlögl R, Hocking RK, Simonov AN. Evolution of Oxygen–Metal Electron Transfer and Metal Electronic States During Manganese Oxide Catalyzed Water Oxidation Revealed with In Situ Soft X‐Ray Spectroscopy. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201810825] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Marc F. Tesch
- Institut Methoden der MaterialentwicklungHelmholtz Zentrum Berlin für Materialien und Energie Albert-Einstein-Straße 15 12489 Berlin Germany
- Abteilung Heterogene ReaktionenMax-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Shannon A. Bonke
- School of Chemistry and the ARC Centre of Excellence for, Electromaterials ScienceMonash University Victoria 3800 Australia
- Institut NanospektroskopieHelmholtz-Zentrum Berlin für Materialien und Energie Kekuléstraße 5 12489 Berlin Germany
- EPR Research GroupMax-Planck-Institut für Chemische Energiekonversion Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
| | - Travis E. Jones
- Abteilung Anorganische ChemieFritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4–6 14195 Berlin Germany
| | - Maryam N. Shaker
- Institut Methoden der MaterialentwicklungHelmholtz Zentrum Berlin für Materialien und Energie Albert-Einstein-Straße 15 12489 Berlin Germany
- Freie Universität BerlinFachbereich Physik Arnimallee 14 14159 Berlin Germany
| | - Jie Xiao
- Institut Methoden der MaterialentwicklungHelmholtz Zentrum Berlin für Materialien und Energie Albert-Einstein-Straße 15 12489 Berlin Germany
| | - Katarzyna Skorupska
- Abteilung Heterogene ReaktionenMax-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
- Abteilung Anorganische ChemieFritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4–6 14195 Berlin Germany
| | - Rik Mom
- Abteilung Anorganische ChemieFritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4–6 14195 Berlin Germany
| | - Jens Melder
- Institut für Anorganische und Analytische Chemie and Freiburger MaterialforschungszentrumAlbert-Ludwigs-Universität Freiburg Albertstraße 21 79104 Freiburg Germany
| | - Philipp Kurz
- Institut für Anorganische und Analytische Chemie and Freiburger MaterialforschungszentrumAlbert-Ludwigs-Universität Freiburg Albertstraße 21 79104 Freiburg Germany
| | - Axel Knop‐Gericke
- Abteilung Anorganische ChemieFritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4–6 14195 Berlin Germany
| | - Robert Schlögl
- Abteilung Heterogene ReaktionenMax-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
- Abteilung Anorganische ChemieFritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4–6 14195 Berlin Germany
| | - Rosalie K. Hocking
- Department of Chemistry and BiotechnologySwinburne University of Technology John Street Hawthorn Victoria 3122 Australia
| | - Alexandr N. Simonov
- School of Chemistry and the ARC Centre of Excellence for, Electromaterials ScienceMonash University Victoria 3800 Australia
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17
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Tesch MF, Bonke SA, Jones TE, Shaker MN, Xiao J, Skorupska K, Mom R, Melder J, Kurz P, Knop-Gericke A, Schlögl R, Hocking RK, Simonov AN. Evolution of Oxygen-Metal Electron Transfer and Metal Electronic States During Manganese Oxide Catalyzed Water Oxidation Revealed with In Situ Soft X-Ray Spectroscopy. Angew Chem Int Ed Engl 2019; 58:3426-3432. [PMID: 30589176 DOI: 10.1002/anie.201810825] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Indexed: 11/07/2022]
Abstract
Manganese oxide (MnOx ) electrocatalysts are examined herein by in situ soft X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) during the oxidation of water buffered by borate (pH 9.2) at potentials from 0.75 to 2.25 V vs. the reversible hydrogen electrode. Correlation of L-edge XAS data with previous mechanistic studies indicates MnIV is the highest oxidation state involved in the catalytic mechanism. MnOx is transformed into birnessite at 1.45 V and does not undergo further structural phase changes. At potentials beyond this transformation, RIXS spectra show progressive enhancement of charge transfer transitions from oxygen to manganese. Theoretical analysis of these data indicates increased hybridization of the Mn-O orbitals and withdrawal of electron density from the O ligand shell. In situ XAS experiments at the O K-edge provide complementary evidence for such a transition. This step is crucial for the formation of O2 from water.
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Affiliation(s)
- Marc F Tesch
- Institut Methoden der Materialentwicklung, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany.,Abteilung Heterogene Reaktionen, Max-Planck-Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Shannon A Bonke
- School of Chemistry and the ARC Centre of Excellence for, Electromaterials Science, Monash University, Victoria, 3800, Australia.,Institut Nanospektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Kekuléstraße 5, 12489, Berlin, Germany.,EPR Research Group, Max-Planck-Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Travis E Jones
- Abteilung Anorganische Chemie, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Maryam N Shaker
- Institut Methoden der Materialentwicklung, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany.,Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14159, Berlin, Germany
| | - Jie Xiao
- Institut Methoden der Materialentwicklung, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Katarzyna Skorupska
- Abteilung Heterogene Reaktionen, Max-Planck-Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany.,Abteilung Anorganische Chemie, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Rik Mom
- Abteilung Anorganische Chemie, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Jens Melder
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Philipp Kurz
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Axel Knop-Gericke
- Abteilung Anorganische Chemie, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Robert Schlögl
- Abteilung Heterogene Reaktionen, Max-Planck-Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany.,Abteilung Anorganische Chemie, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Swinburne University of Technology, John Street, Hawthorn, Victoria, 3122, Australia
| | - Alexandr N Simonov
- School of Chemistry and the ARC Centre of Excellence for, Electromaterials Science, Monash University, Victoria, 3800, Australia
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18
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Zhuang L, Jia Y, Liu H, Wang X, Hocking RK, Liu H, Chen J, Ge L, Zhang L, Li M, Dong CL, Huang YC, Shen S, Yang D, Zhu Z, Yao X. Defect-Induced Pt-Co-Se Coordinated Sites with Highly Asymmetrical Electronic Distribution for Boosting Oxygen-Involving Electrocatalysis. Adv Mater 2019; 31:e1805581. [PMID: 30488551 DOI: 10.1002/adma.201805581] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/10/2018] [Indexed: 06/09/2023]
Abstract
Rational design and synthesis of hetero-coordinated moieties at the atomic scale can significantly raise the performance of the catalyst and obtain mechanistic insight into the oxygen-involving electrocatalysis. Here, a facile plasma-photochemical strategy is applied to construct atomically coordinated Pt-Co-Se moieties in defective CoSe2 (CoSe2- x ) through filling the plasma-created Se vacancies in CoSe2- x with single Pt atomic species (CoSe2- x -Pt) under ultraviolet irradiation. The filling of single Pt can remarkably enhance the oxygen evolution reaction (OER) activity of CoSe2 . Optimal OER specific activity is achieved with a Pt content of 2.25 wt% in CoSe2- x -Pt, exceeding that of CoSe2- x by a factor of 9. CoSe2- x -Pt shows much better OER performance than CoSe2- x filled with single Ni and even Ru atomic species (CoSe2- x -Ni and CoSe2- x -Ru). Noticeably, it is general that Pt is not a good OER catalyst but Ru is; thus the design of active sites for electrocatalysis at an atomic level should follow a different intrinsic mechanism. Mechanism studies unravel that the single Pt can induce much higher electronic distribution asymmetry degree than both single Ni and Ru, and benefit the interaction between the Co sites and adsorbates (OH*, O*, and OOH*) during the OER process, leading to a better OER activity.
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Affiliation(s)
- Linzhou Zhuang
- School of Chemical Engineering, the University of Queensland, Brisbane, 4072, Australia
| | - Yi Jia
- School of Environment and Sciences, and Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, Nathan, 4111, Australia
| | - Hongli Liu
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province, Institute of Marine Biobased Materials, School of Environmental Science and Engineering, Qingdao University, Shandong, 266071, P. R. China
| | - Xin Wang
- School of Environment and Sciences, and Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, Nathan, 4111, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Melbourne, Victoria, 3122, Australia
| | - Hongwei Liu
- Australian Centre for Microscopy & Microanalysis (ACMM), The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jun Chen
- Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Innovation Campus, Wollongong, NSW, 2522, Australia
| | - Lei Ge
- School of Chemical Engineering, the University of Queensland, Brisbane, 4072, Australia
| | - Longzhou Zhang
- School of Environment and Sciences, and Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, Nathan, 4111, Australia
| | - Mengran Li
- School of Chemical Engineering, the University of Queensland, Brisbane, 4072, Australia
| | - Chung-Li Dong
- Department of Physics, Tamkang University, 151 Yingzhuan Road, New Taipei City, 25137, Taiwan, ROC
| | - Yu-Cheng Huang
- Department of Physics, Tamkang University, 151 Yingzhuan Road, New Taipei City, 25137, Taiwan, ROC
| | - Shaohua Shen
- International Research Centre of Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi, 710049, P. R. China
| | - Dongjiang Yang
- Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province, Institute of Marine Biobased Materials, School of Environmental Science and Engineering, Qingdao University, Shandong, 266071, P. R. China
| | - Zhonghua Zhu
- School of Chemical Engineering, the University of Queensland, Brisbane, 4072, Australia
| | - Xiangdong Yao
- School of Environment and Sciences, and Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, Nathan, 4111, Australia
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19
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Shaker MN, Bonke SA, Xiao J, Khan MA, Hocking RK, Tesch MF. Insight into pH-Dependent Formation of Manganese Oxide Phases in Electrodeposited Catalytic Films Probed by Soft X-Ray Absorption Spectroscopy. Chempluschem 2018; 83:721-727. [DOI: 10.1002/cplu.201800055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/06/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Maryam N. Shaker
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Institut Solare Brennstoffe; Hahn-Meitner Platz 1 14109 Berlin Germany
- Freie Universität Berlin; Fachbereich Physik; Arnimallee 14 14159 Berlin Germany
| | - Shannon A. Bonke
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Institut Nanospektroskopie; Kekuléstrasse 5 12489 Berlin Germany
| | - Jie Xiao
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Institut Methoden der Materialentwicklung; Albert-Einstein-Strasse 15 12489 Berlin Germany
| | - Munirah A. Khan
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Institut Methoden der Materialentwicklung; Albert-Einstein-Strasse 15 12489 Berlin Germany
| | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology; Swinburne University of Technology; Hawthorn Melbourne VIC 3122 Australia
| | - Marc F. Tesch
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Institut Methoden der Materialentwicklung; Albert-Einstein-Strasse 15 12489 Berlin Germany
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20
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Sabri M, King HJ, Gummow RJ, Malherbe F, Hocking RK. The Oxidation of Peroxide by Disordered Metal Oxides: A Measurement of Thermodynamic Stability “By Proxy”. Chempluschem 2018; 83:620-629. [DOI: 10.1002/cplu.201800150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/25/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Mayada Sabri
- Department of Chemistry and Biotechnology, Faculty of Science Engineering and Technology; Swinburne University of Technology; Hawthorn, Melbourne VIC 3122 Australia
- College of Science, Technology, and Engineering; James Cook University; Townsville QLD 4811 Australia
- University of Baghdad; College of Education for Pure Science; Ibn Al-Haitham Iraq
| | - Hannah J. King
- Department of Chemistry and Biotechnology, Faculty of Science Engineering and Technology; Swinburne University of Technology; Hawthorn, Melbourne VIC 3122 Australia
- College of Science, Technology, and Engineering; James Cook University; Townsville QLD 4811 Australia
| | - Rosalind J. Gummow
- College of Science, Technology, and Engineering; James Cook University; Townsville QLD 4811 Australia
| | - François Malherbe
- Department of Chemistry and Biotechnology, Faculty of Science Engineering and Technology; Swinburne University of Technology; Hawthorn, Melbourne VIC 3122 Australia
| | - Rosalie K. Hocking
- Department of Chemistry and Biotechnology, Faculty of Science Engineering and Technology; Swinburne University of Technology; Hawthorn, Melbourne VIC 3122 Australia
- College of Science, Technology, and Engineering; James Cook University; Townsville QLD 4811 Australia
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21
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Bo X, Li Y, Hocking RK, Zhao C. NiFeCr Hydroxide Holey Nanosheet as Advanced Electrocatalyst for Water Oxidation. ACS Appl Mater Interfaces 2017; 9:41239-41245. [PMID: 29111654 DOI: 10.1021/acsami.7b12629] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
By introducing chromium into a nickel-iron layered double hydroxide (LDH), a nickel iron chromium hydroxide nanomesh catalyst has been achieved on nickel foam substrate via electrodeposition followed by partial etching of chromium. The electrodeposited chromium acts as a sacrificial template to introduce holes in the LDH to increase the electrochemically active surface area, and the remaining chromium synergistically modulates the electronic structure of the composite. The obtained electrode shows extraordinary performance for oxygen evolution reaction and excellent electrochemical stability. The onset potential of the as-prepared electrode in 1 M KOH is only 1.43 V vs RHE, and the overpotential to achieve a high current density of 100 mA·cm-2 is only 255 mV, outperforming benchmark nonprecious NiFe hydroxide composite electrode in alkaline media.
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Affiliation(s)
- Xin Bo
- School of Chemistry, The University of New South Wales , Sydney, NSW 2052, Australia
| | - Yibing Li
- School of Chemistry, The University of New South Wales , Sydney, NSW 2052, Australia
| | - Rosalie K Hocking
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering & Technology, Swinburne University of Technology , Hawthorn, Melbourne, VIC 3122, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales , Sydney, NSW 2052, Australia
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22
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Simonov AN, Hocking RK, Tao L, Gengenbach T, Williams T, Fang XY, King HJ, Bonke SA, Hoogeveen DA, Romano CA, Tebo BM, Martin LL, Casey WH, Spiccia L. Tunable Biogenic Manganese Oxides. Chemistry 2017; 23:13482-13492. [PMID: 28722330 DOI: 10.1002/chem.201702579] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 11/08/2022]
Abstract
Influence of the conditions for aerobic oxidation of Mn2+(aq) catalysed by the MnxEFG protein complex on the morphology, structure and reactivity of the resulting biogenic manganese oxides (MnOx ) is explored. Physical characterisation of MnOx includes scanning and transmission electron microscopy, and X-ray photoelectron and K-edge Mn, Fe X-ray absorption spectroscopy. This characterisation reveals that the MnOx materials share the structural features of birnessite, yet differ in the degree of structural disorder. Importantly, these biogenic products exhibit strikingly different morphologies that can be easily controlled. Changing the substrate-to-protein ratio produces MnOx either as nm-thin sheets, or rods with diameters below 20 nm, or a combination of the two. Mineralisation in solutions that contain Fe2+(aq) makes solids with significant disorder in the structure, while the presence of Ca2+(aq) facilitates formation of more ordered materials. The (photo)oxidation and (photo)electrocatalytic capacity of the MnOx minerals is examined and correlated with their structural properties.
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Affiliation(s)
- Alexandr N Simonov
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | - Rosalie K Hocking
- Discipline of Chemistry, College of Science and Engineering, James Cook University, Queensland, 4811, Australia
| | - Lizhi Tao
- Department of Chemistry, University of California, One Shields Avenue, Davis, California, 95616, USA
| | - Thomas Gengenbach
- Commonwealth Scientific and Industrial Research Organisation Manufacturing Flagship, Clayton, Victoria, 3168, Australia
| | - Timothy Williams
- Monash Centre for Electron Microscopy, Monash University, Victoria, 3800, Australia
| | - Xi-Ya Fang
- Monash Centre for Electron Microscopy, Monash University, Victoria, 3800, Australia
| | - Hannah J King
- Discipline of Chemistry, College of Science and Engineering, James Cook University, Queensland, 4811, Australia
| | - Shannon A Bonke
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | - Dijon A Hoogeveen
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | - Christine A Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon, 97239, USA
| | - Bradley M Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon, 97239, USA
| | - Lisandra L Martin
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | - William H Casey
- Department of Chemistry, University of California, One Shields Avenue, Davis, California, 95616, USA.,Department of Earth and Planetary Sciences, University of California, One Shields Avenue, Davis, California, 95616, USA
| | - Leone Spiccia
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
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23
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Wang L, Mitoraj D, Turner S, Khavryuchenko OV, Jacob T, Hocking RK, Beranek R. Ultrasmall CoO(OH)x Nanoparticles As a Highly Efficient “True” Cocatalyst in Porous Photoanodes for Water Splitting. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01466] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lidong Wang
- Faculty
of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany
| | - Dariusz Mitoraj
- Faculty
of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany
- Institute
of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
| | - Stuart Turner
- EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | | | - Timo Jacob
- Institute
of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
| | - Rosalie K. Hocking
- Matter
and Materials Group, College of Science, Technology and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Radim Beranek
- Faculty
of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany
- Institute
of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
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24
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King HJ, Bonke SA, Chang SLY, Spiccia L, Johannessen B, Hocking RK. Engineering Disorder into Heterogenite-Like Cobalt Oxides by Phosphate Doping: Implications for the Design of Water-Oxidation Catalysts. ChemCatChem 2016. [DOI: 10.1002/cctc.201600983] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hannah J. King
- Discipline of Chemistry; College of Science and Engineering; James Cook University; 1 James Cook Drive 4811 Townsville Australia
| | - Shannon A. Bonke
- School of Chemistry and; ARC Centre of Excellence for Electromaterials Science (ACES); Monash University; Wellington Road 3800 Melbourne Australia
| | - Shery L. Y. Chang
- LeRoy Eyring Center for Solid State Science; Arizona State University; 901 S. Palm Walk AZ 85281 Tempe USA
| | - Leone Spiccia
- School of Chemistry and; ARC Centre of Excellence for Electromaterials Science (ACES); Monash University; Wellington Road 3800 Melbourne Australia
| | | | - Rosalie K. Hocking
- Discipline of Chemistry; College of Science and Engineering; James Cook University; 1 James Cook Drive 4811 Townsville Australia
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25
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Chang SLY, Barnard AS, Dwyer C, Boothroyd CB, Hocking RK, Ōsawa E, Nicholls RJ. Counting vacancies and nitrogen-vacancy centers in detonation nanodiamond. Nanoscale 2016; 8:10548-52. [PMID: 27147128 PMCID: PMC5048336 DOI: 10.1039/c6nr01888b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Detonation nanodiamond particles (DND) contain highly-stable nitrogen-vacancy (N-V) centers, making it important for quantum-optical and biotechnology applications. However, due to the small particle size, the N-V concentrations are believed to be intrinsically very low, spawning efforts to understand the formation of N-V centers and vacancies, and increase their concentration. Here we show that vacancies in DND can be detected and quantified using simulation-aided electron energy loss spectroscopy. Despite the small particle size, we find that vacancies exist at concentrations of about 1 at%. Based on this experimental finding, we use ab initio calculations to predict that about one fifth of vacancies in DND form N-V centers. The ability to directly detect and quantify vacancies in DND, and predict the corresponding N-V formation probability, has a significant impact to those emerging technologies where higher concentrations and better dispersion of N-V centres are critically required.
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Affiliation(s)
- Shery L Y Chang
- Leroy Eyring Center for Solid State Science, Arizona State University, Tempe, USA.
| | | | | | - Chris B Boothroyd
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany
| | - Rosalie K Hocking
- College of Science Technology and Engineering, James Cook University, Townsville, Australia
| | - Eiji Ōsawa
- NanoCarbon Research Institute, Ueda, Japan
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26
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Singh A, Fekete M, Gengenbach T, Simonov AN, Hocking RK, Chang SLY, Rothmann M, Powar S, Fu D, Hu Z, Wu Q, Cheng YB, Bach U, Spiccia L. Catalytic Activity and Impedance Behavior of Screen-Printed Nickel Oxide as Efficient Water Oxidation Catalysts. ChemSusChem 2015; 8:4266-4274. [PMID: 26617200 DOI: 10.1002/cssc.201500835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Indexed: 06/05/2023]
Abstract
We report that films screen printed from nickel oxide (NiO) nanoparticles and microballs are efficient electrocatalysts for water oxidation under near-neutral and alkaline conditions. Investigations of the composition and structure of the screen-printed films by X-ray diffraction, X-ray absorption spectroscopy, and scanning electron microscopy confirmed that the material was present as the cubic NiO phase. Comparison of the catalytic activity of the microball films to that of films fabricated by using NiO nanoparticles, under similar experimental conditions, revealed that the microball films outperform nanoparticle films of similar thickness owing to a more porous structure and higher surface area. A thinner, less-resistive NiO nanoparticle film, however, was found to have higher activity per Ni atom. Anodization in borate buffer significantly improved the activity of all three films. X-ray photoelectron spectroscopy showed that during anodization, a mixed nickel oxyhydroxide phase formed on the surface of all films, which could account for the improved activity. Impedance spectroscopy revealed that surface traps contribute significantly to the resistance of the NiO films. On anodization, the trap state resistance of all films was reduced, which led to significant improvements in activity. In 1.00 m NaOH, both the microball and nanoparticle films exhibit high long-term stability and produce a stable current density of approximately 30 mA cm(-2) at 600 mV overpotential.
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Affiliation(s)
- Archana Singh
- School of Chemistry, Monash University, Victoria, 3800, Australia.
- Australian Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia.
- Advanced Materials and Processing Research Institute, CSIR, Bhopal, India.
| | - Monika Fekete
- School of Chemistry, Monash University, Victoria, 3800, Australia
- Australian Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | | | - Alexandr N Simonov
- School of Chemistry, Monash University, Victoria, 3800, Australia
- Australian Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
| | - Rosalie K Hocking
- School of Chemistry, Monash University, Victoria, 3800, Australia
- Australian Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia
- School of Chemistry, James Cook University, Townsville, Queensland, 4811, Australia
| | - Shery L Y Chang
- School of Chemistry, Monash University, Victoria, 3800, Australia
| | - Mathias Rothmann
- Department of Materials Science and Engineering, Monash University, Victoria, 3800, Australia
| | - Satvasheel Powar
- School of Chemistry, Monash University, Victoria, 3800, Australia
| | - Dongchuan Fu
- Department of Materials Science and Engineering, Monash University, Victoria, 3800, Australia
| | - Zheng Hu
- Key Lab of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China
| | - Qiang Wu
- Key Lab of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China
| | - Yi-Bing Cheng
- Department of Materials Science and Engineering, Monash University, Victoria, 3800, Australia
- Key Lab of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China
| | - Udo Bach
- Manufacturing Flagship, CSIRO, Clayton, Victoria, 3168, Australia
- Department of Materials Science and Engineering, Monash University, Victoria, 3800, Australia
- Melbourne Centre for Nanofabrication, Clayton, Victoria, 3168, Australia
| | - Leone Spiccia
- School of Chemistry, Monash University, Victoria, 3800, Australia.
- Australian Centre of Excellence for Electromaterials Science, Monash University, Victoria, 3800, Australia.
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27
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Bonke SA, Wiechen M, Hocking RK, Fang XY, Lupton DW, MacFarlane DR, Spiccia L. Electrosynthesis of highly transparent cobalt oxide water oxidation catalyst films from cobalt aminopolycarboxylate complexes. ChemSusChem 2015; 8:1394-1403. [PMID: 25826458 DOI: 10.1002/cssc.201403188] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/22/2015] [Indexed: 06/04/2023]
Abstract
Efficient catalysis of water oxidation represents one of the major challenges en route to efficient sunlight-driven water splitting. Cobalt oxides (CoOx ) have been widely investigated as water oxidation catalysts, although the incorporation of these materials into photoelectrochemical devices has been hindered by a lack of transparency. Herein, the electrosynthesis of transparent CoOx catalyst films is described by utilizing cobalt(II) aminopolycarboxylate complexes as precursors to the oxide. These complexes allow control over the deposition rate and morphology to enable the production of thin, catalytic CoOx films on a conductive substrate, which can be exploited in integrated photoelectrochemical devices. Notably, under a bias of 1.0 V (vs. Ag/AgCl), the film deposited from [Co(NTA)(OH2 )2 ](-) (NTA=nitrilotriacetate) decreased the transmission by only 10 % at λ=500 nm, but still generated >80 % of the water oxidation current produced by a [Co(OH2 )6 ](2+) -derived oxide film whose transmission was only 40 % at λ=500 nm.
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Affiliation(s)
- Shannon A Bonke
- School of Chemistry, Monash University, Victoria, 3800 (Australia); ARC Centre of Excellence for Electromaterials Science (ACES), Monash University, Victoria, 3800 (Australia)
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28
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Lifa T, Tieu W, Hocking RK, Codd R. Forward and Reverse (Retro) Iron(III) or Gallium(III) Desferrioxamine E and Ring-Expanded Analogues Prepared Using Metal-Templated Synthesis from endo-Hydroxamic Acid Monomers. Inorg Chem 2015; 54:3573-83. [DOI: 10.1021/acs.inorgchem.5b00141] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tulip Lifa
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - William Tieu
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rosalie K. Hocking
- College of Science, Technology & Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Rachel Codd
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
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29
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Hocking RK, King HJ, Hesson A, Bonke SA, Johannessen B, Fekete M, Spiccia L, Chang SLY. Engineering Disorder at a Nanoscale: A Combined TEM and XAS Investigation of Amorphous versus Nanocrystalline Sodium Birnessite. Aust J Chem 2015. [DOI: 10.1071/ch15412] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The term amorphous metal oxide is becoming widely used in the catalysis community. The term is generally used when there are no apparent peaks in an X-ray diffraction pattern. However, the absence of such features in X-ray diffraction can mean that the material is either truly amorphous or that it is better described as nanocrystalline. By coprecipitating a sodium birnessite-like phase with and without phosphate (1.5 %), we are able to engineer two very similar but distinct materials – one that is nanocrystalline and the other that is amorphous. The two closely related phases were characterized with both Mn K-edge X-ray absorption spectroscopy and high-resolution transmission electron microscopy. These structural results were then correlated with catalytic and electrocatalytic activities for water oxidation catalysis. In this case, the amorphous phosphate-doped material was less catalytically active than the nanocrystalline material.
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30
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Hocking RK, Malaeb R, Gates WP, Patti AF, Chang SLY, Devlin G, MacFarlane DR, Spiccia L. Formation of a Nanoparticulate Birnessite-Like Phase in Purported Molecular Water Oxidation Catalyst Systems. ChemCatChem 2014. [DOI: 10.1002/cctc.201400066] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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Alley KG, Poneti G, Robinson PSD, Nafady A, Moubaraki B, Aitken JB, Drew SC, Ritchie C, Abrahams BF, Hocking RK, Murray KS, Bond AM, Harris HH, Sorace L, Boskovic C. Redox Activity and Two-Step Valence Tautomerism in a Family of Dinuclear Cobalt Complexes with a Spiroconjugated Bis(dioxolene) Ligand. J Am Chem Soc 2013; 135:8304-23. [DOI: 10.1021/ja4021155] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Giordano Poneti
- UdR INSTM and Department of
Chemistry “U. Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
- Department of Applied Science
and Technology, Guglielmo Marconi University, 00193, Rome, Italy
| | | | - Ayman Nafady
- School
of Chemistry, Monash University, Clayton,
Victoria, 3800, Australia
| | - Boujemaa Moubaraki
- School
of Chemistry, Monash University, Clayton,
Victoria, 3800, Australia
| | - Jade B. Aitken
- School of Chemistry, The University of Sydney, New South Wales, 2006, Australia
| | | | | | | | - Rosalie K. Hocking
- School
of Chemistry, Monash University, Clayton,
Victoria, 3800, Australia
| | - Keith S. Murray
- School
of Chemistry, Monash University, Clayton,
Victoria, 3800, Australia
| | - Alan M. Bond
- School
of Chemistry, Monash University, Clayton,
Victoria, 3800, Australia
| | - Hugh H. Harris
- School of Chemistry and Physics, The University of Adelaide, South Australia, 5005,
Australia
| | - Lorenzo Sorace
- UdR INSTM and Department of
Chemistry “U. Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
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32
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Zhou F, Izgorodin A, Hocking RK, Armel V, Spiccia L, Macfarlane DR. Improvement of catalytic water oxidation on MnOx films by heat treatment. ChemSusChem 2013; 6:643-651. [PMID: 23460606 DOI: 10.1002/cssc.201200849] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 12/19/2012] [Indexed: 06/01/2023]
Abstract
Manganese oxides (MnOx ) are considered to be promising catalysts for water oxidation. Electrodeposited MnOx films from aqueous electrolytes have previously been shown to exhibit a lower catalytic action than films deposited from ionic liquids when tested in strongly alkaline conditions. In this study, we describe a thermal treatment that converts the MnOx films deposited from aqueous electrolytes to highly catalytic films with comparable activity to ionic-liquid-deposited films. The films deposited from aqueous electrolytes show a remarkable improvement in the catalysis of water oxidation after heat treatment at a low temperature (≤120 °C) for 30 min. The films were characterised by using XRD and SEM, and energy-dispersive X-ray (EDX), FTIR and Raman spectroscopy, which indicate that dehydration occurs during the heat treatment without significant change to the microstructure or bulk composition. The X-ray absorption spectroscopy (XAS) results show the growth of small amounts (ca. 3-10 %) of reduced Mn species (Mn(II) or Mn(III) ) after heat treatment. The dehydration process removes structural water and hydroxyl species to result in a conductivity improvement and a more active catalyst, thereby contributing to the enhancement in water oxidation performance.
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Affiliation(s)
- Fengling Zhou
- ARC Centre of Excellence for Electromaterials Science, School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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33
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Wilson SA, Kroll T, Decreau RA, Hocking RK, Lundberg M, Hedman B, Hodgson KO, Solomon EI. Iron L-edge X-ray absorption spectroscopy of oxy-picket fence porphyrin: experimental insight into Fe-O2 bonding. J Am Chem Soc 2013; 135:1124-36. [PMID: 23259487 PMCID: PMC3614349 DOI: 10.1021/ja3103583] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The electronic structure of the Fe-O(2) center in oxy-hemoglobin and oxy-myoglobin is a long-standing issue in the field of bioinorganic chemistry. Spectroscopic studies have been complicated by the highly delocalized nature of the porphyrin, and calculations require interpretation of multideterminant wave functions for a highly covalent metal site. Here, iron L-edge X-ray absorption spectroscopy, interpreted using a valence bond configuration interaction multiplet model, is applied to directly probe the electronic structure of the iron in the biomimetic Fe-O(2) heme complex [Fe(pfp)(1-MeIm)O(2)] (pfp ("picket fence porphyrin") = meso-tetra(α,α,α,α-o-pivalamidophenyl)porphyrin or TpivPP). This method allows separate estimates of σ-donor, π-donor, and π-acceptor interactions through ligand-to-metal charge transfer and metal-to-ligand charge transfer mixing pathways. The L-edge spectrum of [Fe(pfp)(1-MeIm)O(2)] is further compared to those of [Fe(II)(pfp)(1-MeIm)(2)], [Fe(II)(pfp)], and [Fe(III)(tpp)(ImH)(2)]Cl (tpp = meso-tetraphenylporphyrin) which have Fe(II)S = 0, Fe(II)S = 1, and Fe(III)S = 1/2 ground states, respectively. These serve as references for the three possible contributions to the ground state of oxy-pfp. The Fe-O(2) pfp site is experimentally determined to have both significant σ-donation and a strong π-interaction of the O(2) with the iron, with the latter having implications with respect to the spin polarization of the ground state.
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Affiliation(s)
- Samuel A. Wilson
- Department of Chemistry, Stanford University, Stanford, CA 94305, U.S.A
| | - Thomas Kroll
- Department of Chemistry, Stanford University, Stanford, CA 94305, U.S.A
| | | | | | - Marcus Lundberg
- Department of Chemistry, Stanford University, Stanford, CA 94305, U.S.A
| | - Britt Hedman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025-7015, U.S.A
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305, U.S.A
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025-7015, U.S.A
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94305, U.S.A
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025-7015, U.S.A
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34
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Singh A, Chang SLY, Hocking RK, Bach U, Spiccia L. Anodic deposition of NiOx water oxidation catalysts from macrocyclic nickel(ii) complexes. Catal Sci Technol 2013. [DOI: 10.1039/c3cy00017f] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Hocking RK, Gates WP, Cashion JD. Comment on "direct observation of tetrahedrally coordinated Fe(III) in ferrihydrite". Environ Sci Technol 2012; 46:11471-11474. [PMID: 22967048 DOI: 10.1021/es303084e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Rosalie K Hocking
- School of Pharmacy and Molecular Science, James Cook University, Townsville, QLD, 4811, Australia.
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36
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Bonnitcha PD, Kim BJ, Hocking RK, Clegg JK, Turner P, Neville SM, Hambley TW. Cobalt complexes with tripodal ligands: implications for the design of drug chaperones. Dalton Trans 2012; 41:11293-304. [PMID: 22885674 DOI: 10.1039/c2dt30727h] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Extensive research is currently being conducted into metal complexes that can selectively deliver cytotoxins to hypoxic regions in tumours. The development of pharmacologically suitable agents requires an understanding of appropriate ligand-metal systems for chaperoning cytotoxins. In this study, cobalt complexes with tripodal tren (tris-(2-aminoethyl)amine) and tpa (tris-(2-pyridylmethyl)amine) ligands were prepared with ancillary hydroxamic acid, β-diketone and catechol ligands and several parameters, including: pK(a), reduction potential and cytotoxicity were investigated. Fluorescence studies demonstrated that only tpa complexes with β-diketones showed any reduction by ascorbate in situ and similarly, cellular cytotoxicity results demonstrated that ligation to cobalt masked the cytotoxicity of the ancillary groups in all complexes except the tpa diketone derivative [Co(naac)tpa](ClO(4))(2) (naac = 1-methyl-3-(2-naphthyl)propane-1,3-dione). Additionally, it was shown that the hydroxamic acid complexes could be isolated in both the hydroxamate and hydroximate form and the pK(a) values (5.3-8.5) reveal that the reversible protonation/deprotonation of the complexes occurs at physiologically relevant pHs. These results have clear implications for the future design of prodrugs using cobalt moieties as chaperones, providing a basis for the design of cobalt complexes that are both more readily reduced and more readily taken up by cells in hypoxic and acidic environments.
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Affiliation(s)
- Paul D Bonnitcha
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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37
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Alley KG, Poneti G, Aitken JB, Hocking RK, Moubaraki B, Murray KS, Abrahams BF, Harris HH, Sorace L, Boskovic C. A two-step valence tautomeric transition in a dinuclear cobalt complex. Inorg Chem 2012; 51:3944-6. [PMID: 22432512 DOI: 10.1021/ic3002527] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A dinuclear cobalt complex with cobalt centers bridged by a bis(dioxolene) ligand exhibits a rare two-step valence tautomeric transition.
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Affiliation(s)
- Kerwyn G Alley
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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38
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Swiegers GF, MacFarlane DR, Officer DL, Ballantyne A, Boskovic D, Chen J, Dismukes GC, Gardner GP, Hocking RK, Smith PF, Spiccia L, Wagner P, Wallace GG, Winther-Jensen B, Winther-Jensen O. Towards Hydrogen Energy: Progress on Catalysts for Water Splitting. Aust J Chem 2012. [DOI: 10.1071/ch12048] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This article reviews some of the recent work by fellows and associates of the Australian Research Council Centre of Excellence for Electromaterials Science (ACES) at Monash University and the University of Wollongong, as well as their collaborators, in the field of water oxidation and reduction catalysts. This work is focussed on the production of hydrogen for a hydrogen-based energy technology. Topics include: (1) the role and apparent relevance of the cubane-like structure of the Photosystem II Water Oxidation Complex (PSII-WOC) in non-biological homogeneous and heterogeneous water oxidation catalysts, (2) light-activated conducting polymer catalysts for both water oxidation and reduction, and (3) porphyrin-based light harvesters and catalysts.
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39
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Hocking RK, Chang SLY, MacFarlane DR, Spiccia L. Preparation and Characterization of Catalysts for Clean Energy: A Challenge for X-rays and Electrons. Aust J Chem 2012. [DOI: 10.1071/ch12016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
One of the most promising approaches to addressing the challenges of securing cheap and renewable energy sources is to design catalysts from earth abundant materials capable of promoting key chemical reactions including splitting water into hydrogen and oxygen (2H2O → 2H2 + O2) as well as both the oxidation (H2 → 2H+) and reduction (2H+ → H2) of hydrogen. Key to elucidating the origin of catalytic activity and improving catalyst design is determining molecular-level structure, in both the ‘resting state’ and in the functioning ‘active state’ of the catalysts. Herein, we explore some of the analytical challenges important for designing and studying new catalytic materials for making and using hydrogen. We discuss a case study that used the combined approach of X-ray absorption spectroscopy and transmission electron microscopy to understand the fate of the molecular cluster, [Mn4O4L6]+, in Nafion.
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Ohlin CA, Harley SJ, McAlpin JG, Hocking RK, Mercado BQ, Johnson RL, Villa EM, Fidler MK, Olmstead MM, Spiccia L, Britt RD, Casey WH. Rates of water exchange for two cobalt(II) heteropolyoxotungstate compounds in aqueous solution. Chemistry 2011; 17:4408-17. [PMID: 21416515 DOI: 10.1002/chem.201003550] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Indexed: 11/12/2022]
Abstract
Polyoxometalate ions are used as ligands in water-oxidation processes related to solar energy production. An important step in these reactions is the association and dissociation of water from the catalytic sites, the rates of which are unknown. Here we report the exchange rates of water ligated to Co(II) atoms in two polyoxotungstate sandwich molecules using the (17)O-NMR-based Swift-Connick method. The compounds were the [Co(4)(H(2)O)(2)(B-α-PW(9)O(34))(2)](10-) and the larger αββα-[Co(4)(H(2)O)(2)(P(2)W(15)O(56))(2)](16-) ions, each with two water molecules bound trans to one another in a Co(II) sandwich between the tungstate ligands. The clusters, in both solid and solution state, were characterized by a range of methods, including NMR, EPR, FT-IR, UV-Vis, and EXAFS spectroscopy, ESI-MS, single-crystal X-ray crystallography, and potentiometry. For [Co(4)(H(2)O)(2)(B-α-PW(9)O(34))(2)](10-) at pH 5.4, we estimate: k(298)=1.5(5)±0.3×10(6) s(-1), ΔH(≠)=39.8±0.4 kJ mol(-1), ΔS(≠)=+7.1±1.2 J mol(-1) K(-1) and ΔV(≠)=5.6 ±1.6 cm(3) mol(-1). For the Wells-Dawson sandwich cluster (αββα-[Co(4)(H(2)O)(2)(P(2)W(15)O(56))(2)](16-)) at pH 5.54, we find: k(298)=1.6(2)±0.3×10(6) s(-1), ΔH(≠)=27.6±0.4 kJ mol(-1) ΔS(≠)=-33±1.3 J mol(-1) K(-1) and ΔV(≠)=2.2±1.4 cm(3) mol(-1) at pH 5.2. The molecules are clearly stable and monospecific in slightly acidic solutions, but dissociate in strongly acidic solutions. This dissociation is detectable by EPR spectroscopy as S=3/2 Co(II) species (such as the [Co(H(2)O)(6)](2+) monomer ion) and by the significant reduction of the Co-Co vector in the XAS spectra.
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Affiliation(s)
- C André Ohlin
- Department of Chemistry, University of California, Davis, California 95616, USA
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41
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Hocking RK, DeBeer George S, Gross Z, Walker FA, Hodgson KO, Hedman B, Solomon EI. Fe L- and K-edge XAS of low-spin ferric corrole: bonding and reactivity relative to low-spin ferric porphyrin. Inorg Chem 2010; 48:1678-88. [PMID: 19149467 DOI: 10.1021/ic802248t] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Corrole is a tetrapyrrolic macrocycle that has one carbon atom less than a porphyrin. The ring contraction reduces the symmetry from D(4h) to C(2v), changes the electronic structure of the heterocycle, and leads to a smaller central cavity with three protons rather than the two of a porphyrin. The differences between ferric corroles and porphyrins lead to a number of differences in reactivity including increased axial ligand lability and a tendency to form 5-coordinate complexes. The electronic structure origin of these differences has been difficult to study experimentally as the dominant porphyrin/corrole pi --> pi* transitions obscure the electronic transitions of the metal. Recently, we have developed a methodology that allows for the interpretation of the multiplet structure of Fe L-edges in terms of differential orbital covalency (i.e., the differences in mixing of the metal d orbitals with the ligand valence orbitals) using a valence bond configuration interaction model. Herein, we apply this methodology, combined with a ligand field analysis of the Fe K pre-edge to a low-spin ferric corrole, and compare it to a low-spin ferric porphyrin. The experimental results combined with DFT calculations show that the contracted corrole is both a stronger sigma donor and a very anisotropic pi donor. These differences decrease the bonding interactions with axial ligands and contribute to the increased axial ligand lability and reactivity of ferric corroles relative to ferric porphyrins.
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Affiliation(s)
- Rosalie K Hocking
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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42
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Hocking RK, DeBeer George S, Raymond KN, Hodgson KO, Hedman B, Solomon EI. Fe L-edge X-ray absorption spectroscopy determination of differential orbital covalency of siderophore model compounds: electronic structure contributions to high stability constants. J Am Chem Soc 2010; 132:4006-15. [PMID: 20187651 PMCID: PMC2890247 DOI: 10.1021/ja9090098] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Most bacteria and fungi produce low-molecular-weight iron chelators called siderophores. Although different siderophore structures have been characterized, the iron-binding moieties often contain catecholate or hydroxamate groups. Siderophores function because of their extraordinarily high stability constants (K(STAB) = 10(30)-10(49)) and selectivity for Fe(III), yet the origin of these high stability constants has been difficult to quantify experimentally. Herein, we utilize Fe L-edge X-ray absorption spectroscopy to determine the differential orbital covalency (i.e., the differences in the mixing of the metal d-orbitals with ligand valence orbitals) of a series of siderophore model compounds. The results enable evaluation of the electronic structure contributions to their high stability constants in terms of sigma- and pi-donor covalent bonding, ionic bonding, and solvent effects. The results indicate substantial differences in the covalent contributions to stability constants of hydroxamate and catecholate complexes and show that increased sigma as well as pi bonding contributes to the high stability constants of catecholate complexes.
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Affiliation(s)
- Rosalie K Hocking
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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43
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Johnston SG, Keene AF, Burton ED, Bush RT, Sullivan LA, McElnea A, Ahern CR, Smith CD, Powell B, Hocking RK. Arsenic mobilization in a seawater inundated acid sulfate soil. Environ Sci Technol 2010; 44:1968-1973. [PMID: 20155899 DOI: 10.1021/es903114z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Tidal seawater inundation of coastal acid sulfate soils can generate Fe- and S0(4)-reducing conditions in previously oxic-acidic sediments. This creates potential for mobilization of As during the redox transition. We explore the consequences for As by investigating the hydrology, porewater geochemistry, solid-phase speciation, and mineralogical partitioning of As across two tidal fringe toposequences. Seawater inundation induced a tidally controlled redox gradient Maximum porewater As (~400 μg/L) occurred in the shallow (<1 m), intertidal, redox transition zone between Fe-oxidizing and S0(4)-reducing conditions. Primary mechanisms of As mobilization include the reduction of solid-phase As(V) to As(lll), reductive dissolution of As(V)-bearing secondary Fe(lll) minerals and competitive anion desorption. Porewater As concentrations decreased in the zone of contemporary pyrite reformation. Oscillating hydraulic gradients caused by tidal pumping promote upward advection of As and Fe(2+)-enriched porewater in the intertidal zone, leading to accumulation of As(V)-enriched Fe(lll) (hydr)oxides at the oxic sediment-water interface. While this provides a natural reactive-Fe barrier, it does not completely retard the flux of porewater As to overtopping surface waters. Furthermore, the accumulated Fe minerals may be prone to future reductive dissolution. A conceptual model describing As hydro-geochemical coupling across an intertidal fringe is presented.
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Affiliation(s)
- Scott G Johnston
- Southern Cross GeoScience, Southern Cross University, Lismore, NSW 2480, Australia.
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44
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Burton ED, Bush RT, Johnston SG, Watling KM, Hocking RK, Sullivan LA, Parker GK. Sorption of arsenic(V) and arsenic(III) to schwertmannite. Environ Sci Technol 2009; 43:9202-7. [PMID: 19921855 DOI: 10.1021/es902461x] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study describes the sorption of As(V) and As(III) to schwertmannite as a function of pH and arsenic loading. In general, sorption of As(V) was greatest at low pH, whereas high pH favored the sorption of As(III). The actual pH of equivalent As(V) and As(III) sorption was strongly loading dependent, decreasing from pH approximately 8.0 at loadings <120 mmol(As) mol(Fe)(-1) to pH approximately 4.6 at a loading of 380 mmol(As) mol(Fe)(-1). Sorption isotherms for As(V) were characterized by strong partitioning to the schwertmannite solid-phase at low loadings and sorption capacities of 225-330 mmol(As(V)) mol(Fe)(-1) at high loadings. In contrast, the As(III) isotherms revealed a weak affinity for sorption of As(III) versus As(V) at low loadings yet a greater affinity for As(III) sorption compared with As(V) at high loadings (when pH > 4.6). Sorption of As(V) and As(III) caused significant release of SO(4)(2-) from within the schwertmannite solid-phase, without major degradation of the schwertmannite structure (as evident by X-ray diffraction and Raman spectroscopy). This can be interpreted as arsenic sorption via incorporation into the schwertmannite structure, rather than merely surface complexation at the mineral-water interface. The results of this study have important implications for arsenic mobility in the presence of schwertmannite, such as in areas affected by acid-mine drainage and acid-sulfate soils. In particular, arsenic speciation, arsenic loading, and pH should be considered when predicting and managing arsenic mobility in schwertmannite-rich systems.
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Affiliation(s)
- Edward D Burton
- Southern Cross GeoScience, Southern Cross University, Lismore, NSW 2480, Australia.
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45
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Morgan KE, Burton ED, Cook P, Raven MD, Fitzpatrick RW, Bush R, Sullivan LA, Hocking RK. Fe and S K-edge XAS determination of iron-sulfur species present in a range of acid sulfate soils: Effects of particle size and concentration on quantitative XANES determinations. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/190/1/012144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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46
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Burton ED, Bush RT, Sullivan LA, Hocking RK, Mitchell DRG, Johnston SG, Fitzpatrick RW, Raven M, McClure S, Jang LY. Iron-monosulfide oxidation in natural sediments: resolving microbially mediated S transformations using XANES, electron microscopy, and selective extractions. Environ Sci Technol 2009; 43:3128-3134. [PMID: 19534124 DOI: 10.1021/es8036548] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Iron-monosulfide oxidation and associated S transformations in a natural sediment were examined by combining selective extractions, electron microscopy and S K-edge X-ray absorption near-edge structure (XANES) spectroscopy, The sediment examined in this study was collected from a waterway receiving acid-sulfate soil drainage. It contained a high acid-volatile sulfide content (1031 micromol g(-1)), reflecting an abundance of iron-monosulfide. The iron-monosulfide speciation in the initial sediment sample was dominated by nanocrystalline mackinawite (tetragonal FeS). At near-neutral pH and an 02 partial pressure of approximately 0.2 atm, the mackinawite was found to oxidize rapidly, with a half-time of 29 +/- 2 min. This oxidation rate did not differ significantly (P < 0.05) between abiotic versus biotic conditions, demonstrating that oxidation of nanocrystalline mackinawite was not microbially mediated. The extraction results suggested that elemental S (S8(0)) was a key intermediate S oxidation product Transmission electron microscopy showed the S8(0) to be amorphous nanoglobules, 100-200 nm in diameter. The quantitative importance of S8(0) was confirmed by linear combination XANES spectroscopy, after accounting for the inherent effect of the nanoscale S8(0) particle-size on the corresponding XANES spectrum. Both the selective extraction and XANES data showed that oxidation of S8(0) to SO4(2-) was mediated by microbial activity. In addition to directly revealing important S transformations, the XANES results support the accuracy of the selective extraction scheme employed here.
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Affiliation(s)
- E D Burton
- A Centre for Acid Sulfate Soil Research, Southern Cross GeoScience, Southern Cross University, Lismore, NSW 2480, Australia.
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47
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Sarangi R, Hocking RK, Neidig ML, Benfatto M, Holman TR, Solomon EI, Hodgson KO, Hedman B. Geometric structure determination of N694C lipoxygenase: a comparative near-edge X-ray absorption spectroscopy and extended X-ray absorption fine structure study. Inorg Chem 2008; 47:11543-50. [PMID: 18656914 PMCID: PMC2736335 DOI: 10.1021/ic800580f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mononuclear nonheme iron active site of N694C soybean lipoxygenase (sLO1) has been investigated in the resting ferrous form using a combination of Fe-K-pre-edge, near-edge (using the minuit X-ray absorption near-edge full multiple-scattering approach), and extended X-ray absorption fine structure (EXAFS) methods. The results indicate that the active site is six-coordinate (6C) with a large perturbation in the first-shell bond distances in comparison to the more ordered octahedral site in wild-type sLO1. Upon mutation of the asparagine to cysteine, the short Fe-O interaction with asparagine is replaced by a weak Fe-(H(2)O), which leads to a distorted 6C site with an effective 5C ligand field. In addition, it is shown that near-edge multiple scattering analysis can give important three-dimensional structural information, which usually cannot be accessed using EXAFS analysis. It is further shown that, relative to EXAFS, near-edge analysis is more sensitive to partial coordination numbers and can be potentially used as a tool for structure determination in a mixture of chemical species.
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Affiliation(s)
- Ritimukta Sarangi
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Stanford, CA, 94309, USA
| | | | - Michael L. Neidig
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Maurizio Benfatto
- Laboratori Nazionali di Frascati dell’ INFN, C.P. 13, 00044 Frascati, Italy
| | - Theodore R Holman
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Stanford, CA, 94309, USA
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Stanford, CA, 94309, USA
| | - Britt Hedman
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Stanford, CA, 94309, USA
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48
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Hocking RK, Deeth RJ, Hambley TW. DFT Study of the Systematic Variations in Metal−Ligand Bond Lengths of Coordination Complexes: the Crucial Role of the Condensed Phase. Inorg Chem 2007; 46:8238-44. [PMID: 17764175 DOI: 10.1021/ic701166p] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The experimental M-A and M-B distances in several series of [MAnBm-n]-type complexes have been studied by DFT. Many of the structural features of the series, such as trans influences and sterically induced bond elongations, are not reproduced correctly in gas-phase DFT calculations. However, the correct trends are recovered by explicitly including environmental effects via the COSMO solvation model. These observations imply that the condensed-phase environment plays a critical role in determining the geometric structure of coordination complexes. Thus, any apparently satisfactory reproduction of the condensed-phase structure by an in vacuo calculation may mask an incorrect treatment of the interplay between different ligands attached to the same metal center.
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Affiliation(s)
- Rosalie K Hocking
- CHMR, School of Chemistry, The University of Sydney, 2006, Australia, Department of Chemistry, University of Warwick, Coventry, UK.
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49
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Hocking RK, Hambley TW. Database Analysis of Transition Metal Carbonyl Bond Lengths: Insight into the Periodicity of π Back-Bonding, σ Donation, and the Factors Affecting the Electronic Structure of the TM−C⋮O Moiety. Organometallics 2007. [DOI: 10.1021/om061072n] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rosalie K. Hocking
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - Trevor W. Hambley
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
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50
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Hocking RK, Wasinger EC, Yan YL, Degroot FMF, Walker FA, Hodgson KO, Hedman B, Solomon EI. Fe L-edge X-ray absorption spectroscopy of low-spin heme relative to non-heme Fe complexes: delocalization of Fe d-electrons into the porphyrin ligand. J Am Chem Soc 2007; 129:113-25. [PMID: 17199290 PMCID: PMC2890250 DOI: 10.1021/ja065627h] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hemes (iron porphyrins) are involved in a range of functions in biology, including electron transfer, small-molecule binding and transport, and O2 activation. The delocalization of the Fe d-electrons into the porphyrin ring and its effect on the redox chemistry and reactivity of these systems has been difficult to study by optical spectroscopies due to the dominant porphyrin pi-->pi(*) transitions, which obscure the metal center. Recently, we have developed a methodology that allows for the interpretation of the multiplet structure of Fe L-edges in terms of differential orbital covalency (i.e., differences in mixing of the d-orbitals with ligand orbitals) using a valence bond configuration interaction (VBCI) model. Applied to low-spin heme systems, this methodology allows experimental determination of the delocalization of the Fe d-electrons into the porphyrin (P) ring in terms of both P-->Fe sigma and pi-donation and Fe-->P pi back-bonding. We find that pi-donation to Fe(III) is much larger than pi back-bonding from Fe(II), indicating that a hole superexchange pathway dominates electron transfer. The implications of the results are also discussed in terms of the differences between heme and non-heme oxygen activation chemistry.
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Affiliation(s)
- Rosalie K Hocking
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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