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Choe H, Kim SY, Zhao S, Cha BJ, Grehl T, Brüner P, Kim YD. Surface Structures of Fe-TiO 2 Photocatalysts for NO Oxidation. ACS Appl Mater Interfaces 2022; 14:24028-24038. [PMID: 35549024 DOI: 10.1021/acsami.2c04118] [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] [Indexed: 06/15/2023]
Abstract
Commercial rutile TiO2 particles capped with Al2O3 and ZrO2 layers, which are widely used in white pigments, can serve as a starting material for the fabrication of visible light-responsive photocatalysts toward gas-phase NO oxidation. The as-received TiO2 with iron impurities exhibited reduced photocatalytic activity, and the activity was boosted by the deposition of additional iron comparable in quantity to the intrinsic iron impurity level. Analyses using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectroscopy, and low-energy ion scattering spectroscopy revealed that the deposited iron and intrinsic impurity iron are dissimilar in terms of location, oxidation states, and interaction with TiO2. This suggests that tracking the structure and impurity levels of photocatalyst elements can be crucial for understanding structure-activity relationships of real catalysts.
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Affiliation(s)
- Huicheol Choe
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Soong Yeon Kim
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Shufang Zhao
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Byeong Jun Cha
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
- Center of Scientific Instrumentation, Korea Basic Science Institute, Ochang Center, Cheongju 28119, Chungbuk, Korea
| | - Thomas Grehl
- IONTOF Technologies GmbH, Heisenbergstr. 15, Münster 48149, Germany
| | - Philipp Brüner
- IONTOF Technologies GmbH, Heisenbergstr. 15, Münster 48149, Germany
| | - Young Dok Kim
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
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Bullen JC, Kenney JPL, Fearn S, Kafizas A, Skinner S, Weiss DJ. Improved accuracy in multicomponent surface complexation models using surface-sensitive analytical techniques: Adsorption of arsenic onto a TiO 2/Fe 2O 3 multifunctional sorbent. J Colloid Interface Sci 2020; 580:834-849. [PMID: 32731167 DOI: 10.1016/j.jcis.2020.06.119] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 02/28/2020] [Revised: 06/17/2020] [Accepted: 06/28/2020] [Indexed: 11/17/2022]
Abstract
Novel composite materials are increasingly developed for water treatment applications with the aim of achieving multifunctional behaviour, e.g. combining adsorption with light-driven remediation. The application of surface complexation models (SCM) is important to understand how adsorption changes as a function of pH, ionic strength and the presence of competitor ions. Component additive (CA) models describe composite sorbents using a combination of single-phase reference materials. However, predictive adsorption modelling using the CA-SCM approach remains unreliable, due to challenges in the quantitative determination of surface composition. In this study, we test the hypothesis that characterisation of the outermost surface using low energy ion scattering (LEIS) improves CA-SCM accuracy. We consider the TiO2/Fe2O3 photocatalyst-sorbents that are increasingly investigated for arsenic remediation. Due to an iron oxide surface coating that was not captured by bulk analysis, LEIS significantly improves the accuracy of our component additive predictions for monolayer surface processes: adsorption of arsenic(V) and surface acidity. We also demonstrate non-component additivity in multilayer arsenic(III) adsorption, due to changes in surface morphology/porosity. Our results demonstrate how surface-sensitive analytical techniques will improve adsorption models for the next generation of composite sorbents.
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Affiliation(s)
- Jay C Bullen
- Department of Earth Science and Engineering, Faculty of Engineering, Imperial College London, London SW7 2BX, UK.
| | - Janice P L Kenney
- Department of Physical Sciences, MacEwan University, Edmonton, Alberta T5J 4S2P, Canada
| | - Sarah Fearn
- Department of Materials, Faculty of Engineering, Imperial College London, London SW7 2BX, UK
| | - Andreas Kafizas
- Department of Chemistry, White City Campus, Imperial College London, London W12 OBZ, UK; The Grantham Institute, Imperial College London, London, SW7 2AZ, UK
| | - Stephen Skinner
- Department of Materials, Faculty of Engineering, Imperial College London, London SW7 2BX, UK
| | - Dominik J Weiss
- Department of Earth Science and Engineering, Faculty of Engineering, Imperial College London, London SW7 2BX, UK; Civil and Environmental Engineering, E-Quad, Princeton University, Princeton, USA.
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Ge T, Zhao W, Wu X, Lan X, Zhang Y, Qiang Y, He Y. Incorporation of electroconductive carbon fibers to achieve enhanced anti-corrosion performance of zinc rich coatings. J Colloid Interface Sci 2020; 567:113-125. [PMID: 32044540 DOI: 10.1016/j.jcis.2020.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 11/21/2019] [Revised: 01/13/2020] [Accepted: 02/01/2020] [Indexed: 11/25/2022]
Abstract
Zinc rich epoxy (ZRE) coatings can provide sacrificial anode protection for metal substrate. Electrically conductive fillers can be added into ZRE coatings to create electroconductive network and improve the utilization of zinc particles. Inspired by the structure of reinforced concrete, in this work, carbon fibers with a length of 2 mm, 5 mm, and 10 mm were used as electrically conductive fillers to drive more zinc particle into electrically conductive paths and to provide coatings with better mechanical properties. Without agglomeration, ZRE-10 can achieve an efficient protection for copper substrate up to 50 days in 3.5 wt% NaCl solution, much longer than that of ZRE coating. Moreover, the fraction of water absorbed by ZRE-10 is 14%, which for ZRE is 20%, and the adhesion strength of ZRE-10 increased by 65% compared with that of ZRE. All tests in this work can prove a remarkably enhanced anticorrosion performance and mechanical properties of ZRE coatings achieved by addition of longer carbon fibers.
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Affiliation(s)
- Tianhao Ge
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; School of Material Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Wenjie Zhao
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
| | - Xuedong Wu
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Xijian Lan
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yonggang Zhang
- National Engineering Laboratory Carbon Fiber Preparation Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yujie Qiang
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
| | - Yanlin He
- School of Material Science and Engineering, Shanghai University, Shanghai 200444, China
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Lei Y, Qiu Z, Liu J, Li D, Tan N, Liu T, Zhang Y, Chang X, Gu Y, Yin Y. Effect of Conducting Polyaniline/Graphene Nanosheet Content on the Corrosion Behavior of Zinc-Rich Epoxy Primers in 3.5% NaCl Solution. Polymers (Basel) 2019; 11:polym11050850. [PMID: 31083352 PMCID: PMC6572091 DOI: 10.3390/polym11050850] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/04/2019] [Accepted: 05/06/2019] [Indexed: 11/16/2022] Open
Abstract
The corrosion behavior of zinc-rich epoxy primers or paints (ZRPs) with different conducting polyaniline-grafted graphene (PANI/Gr) contents was investigated. Conductivity of the formed PANI/Gr nanosheets was significantly improved by employing the Gr as the inner template to synthesize the PANI. The protective properties and electrochemical behavior of coatings with artificial defects were investigated by monitoring the free corrosion potential versus time and by using localized electrochemical impedance spectroscopy (LEIS). A synergetic enhancement of the physical barrier role of the coating and the zinc sacrificial cathodic protection was achieved in the case of ZRP including PANI/Gr nanosheets. In addition, the ZRP mixed with the PANI/Gr at a content of 0.6% exhibited the best anticorrosion performance across the range of investigated PANI/Gr contents.
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Affiliation(s)
- Yanhua Lei
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
- Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development, Beijing Institute of Petrochemical Technology, Beijing 102617, China.
| | - Zhichao Qiu
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Jiurong Liu
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Dongdong Li
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Ning Tan
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Tao Liu
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Yuliang Zhang
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Xueting Chang
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Yanhong Gu
- Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development, Beijing Institute of Petrochemical Technology, Beijing 102617, China.
| | - Yansheng Yin
- Institute of Marine Materials Science and Engineering, College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
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Wan H, Song D, Li X, Zhang D, Gao J, Du C. Effect of Zinc Phosphate on the Corrosion Behavior of Waterborne Acrylic Coating/Metal Interface. Materials (Basel) 2017; 10:E654. [PMID: 28773013 DOI: 10.3390/ma10060654] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/05/2022]
Abstract
Waterborne coating has recently been paid much attention. However, it cannot be used widely due to its performance limitations. Under the specified conditions of the selected resin, selecting the function pigment is key to improving the anticorrosive properties of the coating. Zinc phosphate is an environmentally protective and efficient anticorrosion pigment. In this work, zinc phosphate was used in modifying waterborne acrylic coatings. Moreover, the disbonding resistance of the coating was studied. Results showed that adding zinc phosphate can effectively inhibit the anode process of metal corrosion and enhance the wet adhesion of the coating, and consequently prevent the horizontal diffusion of the corrosive medium into the coating/metal interface and slow down the disbonding of the coating.
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Diaz I, Martinez-Lerma JF, Montoya R, Llorente I, Escudero ML, García-Alonso MC. Study of overall and local electrochemical responses of oxide films grown on CoCr alloy under biological environments. Bioelectrochemistry 2017; 115:1-10. [PMID: 28126645 DOI: 10.1016/j.bioelechem.2017.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 09/13/2016] [Revised: 01/16/2017] [Accepted: 01/16/2017] [Indexed: 11/25/2022]
Abstract
The interaction of the physiological medium and living tissues with the implant surfaces in biological environments is regulated by biopotentials that induce changes in the chemical composition, structure and thickness of the oxide film. In this work, oxide films grown on CoCr alloys at 0.5 V vs Ag/AgCl and 0.7 V vs Ag/AgCl have been characterized through overall and localized electrochemical techniques in a phosphate buffer solution and 0.3% hyaluronic acid. Nanopores of 10-50nm diameter are homogeneously distributed along the surface in the oxide film formed at 0.7 V vs Ag/AgCl. The distribution of the Constant Phase Element studied by local electrochemical impedance spectroscopy showed a three-dimensional (3D) model on the oxide films grown at 0.5 V vs Ag/AgCl and 0.7 V vs Ag/AgCl. This behaviour is especially noticeable in oxide films grown at 0.7 V vs Ag/AgCl, probably due to surface inhomogeneities, and resistive properties generated by the potentiostatic growth of the oxide film.
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Affiliation(s)
- I Diaz
- Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Gregorio del Amo, 8, Madrid, Spain
| | - J F Martinez-Lerma
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luís Potosí, S.L.P. Av. Dr. Manuel Nava No. 6, Zona Universitaria, C.P. 78210 San Luis Potosí, S.L.P., Mexico
| | - R Montoya
- Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Gregorio del Amo, 8, Madrid, Spain; Research Group Electrochemical and Surface Engineering, Vrije Universiteit Brussel, Campus Etterbeek Pleinlaan 2, 1050 Brussels, Belgium
| | - I Llorente
- Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Gregorio del Amo, 8, Madrid, Spain
| | - M L Escudero
- Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Gregorio del Amo, 8, Madrid, Spain
| | - M C García-Alonso
- Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Gregorio del Amo, 8, Madrid, Spain.
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Monreal R, Goebl D, Primetzhofer D, Bauer P. Effects of the atomic level shift in the Auger neutralization rates of noble metal surfaces. Nucl Instrum Methods Phys Res B 2013; 315:206-212. [PMID: 25843996 PMCID: PMC4376069 DOI: 10.1016/j.nimb.2013.03.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/04/2013] [Indexed: 06/04/2023]
Abstract
In this work we compare characteristics of Auger neutralization of [Formula: see text] ions at noble metal and free-electron metal surfaces. For noble metals, we find that the position of the energy level of He with respect to the Fermi level has a non-negligible influence on the values of the calculated Auger rates through the evaluation of the surface dielectric susceptibility. We conclude that even though our calculated rates are accurate, further theoretical effort is needed to obtain realistic values of the energy level of He in front of these surfaces.
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Affiliation(s)
- R.C. Monreal
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Centre (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - D. Goebl
- Institut für Experimentalphysik, Abteilung für Atom-und Oberflächenphysik, Johannes Kepler Universität Linz, 4040 Linz, Austria
| | - D. Primetzhofer
- Institut für Experimentalphysik, Abteilung für Atom-und Oberflächenphysik, Johannes Kepler Universität Linz, 4040 Linz, Austria
| | - P. Bauer
- Institut für Experimentalphysik, Abteilung für Atom-und Oberflächenphysik, Johannes Kepler Universität Linz, 4040 Linz, Austria
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