1
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Tort R, Bagger A, Westhead O, Kondo Y, Khobnya A, Winiwarter A, Davies BJV, Walsh A, Katayama Y, Yamada Y, Ryan MP, Titirici MM, Stephens IEL. Searching for the Rules of Electrochemical Nitrogen Fixation. ACS Catal 2023; 13:14513-14522. [PMID: 38026818 PMCID: PMC10660346 DOI: 10.1021/acscatal.3c03951] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/04/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023]
Abstract
Li-mediated ammonia synthesis is, thus far, the only electrochemical method for heterogeneous decentralized ammonia production. The unique selectivity of the solid electrode provides an alternative to one of the largest heterogeneous thermal catalytic processes. However, it is burdened with intrinsic energy losses, operating at a Li plating potential. In this work, we survey the periodic table to understand the fundamental features that make Li stand out. Through density functional theory calculations and experimentation on chemistries analogous to lithium (e.g., Na, Mg, Ca), we find that lithium is unique in several ways. It combines a stable nitride that readily decomposes to ammonia with an ideal solid electrolyte interphase, balancing reagents at the reactive interface. We propose descriptors based on simulated formation and binding energies of key intermediates and further on hard and soft acids and bases (HSAB principle) to generalize such features. The survey will help the community toward electrochemical systems beyond Li for nitrogen fixation.
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Affiliation(s)
- Romain Tort
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Alexander Bagger
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
- Department
of Physics, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Olivia Westhead
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
| | - Yasuyuki Kondo
- Osaka
University, SANKEN (The Institute of Scientific and Industrial Research),
Mihogaoka, Osaka, Ibaraki 567-0047, Japan
| | - Artem Khobnya
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
| | - Anna Winiwarter
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
| | | | - Aron Walsh
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
| | - Yu Katayama
- Osaka
University, SANKEN (The Institute of Scientific and Industrial Research),
Mihogaoka, Osaka, Ibaraki 567-0047, Japan
| | - Yuki Yamada
- Osaka
University, SANKEN (The Institute of Scientific and Industrial Research),
Mihogaoka, Osaka, Ibaraki 567-0047, Japan
| | - Mary P. Ryan
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
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2
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Liu W, Niu X, Feng J, Yin R, Ma S, Que W, Dai J, Tang J, Wu F, Shi W, Liu X, Cao X. Tunable Heterogeneous FeCo Alloy-Mo 0.82N Bifunctional Electrocatalysts for Temperature-Adapted Zn-Air Batteries. ACS Appl Mater Interfaces 2023; 15:15344-15352. [PMID: 36920344 DOI: 10.1021/acsami.2c21616] [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] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The practical applications of temperature-tolerant Zn-air batteries (ZABs) rely on highly active and stable bifunctional catalysts that accelerate cathodic oxygen reduction (ORR) and oxygen evolution (OER) reactions. Herein, we successfully integrated fascinating transition metal nitrides and FeCo alloys through a simple coordination assembly and pyrolysis process. Importantly, the alloy-to-nitride ratio in the heterogeneous catalyst can be carefully regulated through the subsequent etching process. Moreover, the composition-dependent ORR/OER performance of the FeCo-Mo0.82N catalysts was revealed. Aqueous ZABs using the optimized FeCo-Mo0.82N-60 as a cathode exhibit a high peak power density of 149.7 mW cm-2 and an impressive stability of 600 h with a low charge-discharge voltage gap decay rate of 0.025 mV h-1, which exceeds those of most of recent reports. Furthermore, the FeCo-Mo0.82N-60-based flexible ZABs display a small specific capacity degradation (3%) from 40 to -10 °C, demonstrating excellent temperature tolerance.
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Affiliation(s)
- Wenxian Liu
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Xinxin Niu
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jinxiu Feng
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Ruilian Yin
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Suli Ma
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Wenbin Que
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jiale Dai
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jiawei Tang
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Fangfang Wu
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Wenhui Shi
- Center for Membrane and Water Science & Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Xijun Liu
- MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, School of Resource, Environments and Materials, Guangxi University, Nanning 530004, P. R. China
| | - Xiehong Cao
- College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
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3
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Ge Y, Zhang C, Zhu X, Li H, Wang Y. Boron nitride nanotube-salt-water hybrid:crystalline precipitation. Nanotechnology 2023; 34:225402. [PMID: 36808905 DOI: 10.1088/1361-6528/acbda0] [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: 11/09/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Molecular dynamics simulation is used to study the transport characteristics of NaCl solution in boron nitride nanotubes (BNNTs). It presents an interesting and well-supported MD study of the crystallization of NaCl from its water solution under the confinement of a 3 nm thick boron nitride nanotube with varied surface charging conditions. The results of the molecular dynamics simulation indicate that NaCl crystallization occurs in charged BNNTs at room temperature when the concentration of NaCl solution reaches about 1.2 M. The reason for this phenomenon is as follows: when the number of ions in the nanotubes is high, the double electric layer that forms at the nanoscale near the charged wall surface, the hydrophobicity of BNNTs, and the interaction among ions cause ions to aggregate in the nanotubes. As the concentration of NaCl solution increases, the concentration of ions when they aggregate in the nanotubes reaches the saturation concentration of the NaCl solution, resulting in the crystalline precipitation phenomenon.
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Affiliation(s)
- Yanyan Ge
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China
| | - Cuicui Zhang
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China
| | - Xueru Zhu
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China
| | - Hua Li
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China
| | - Yongjian Wang
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China
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4
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Yazawa K, Zakutayev A, Brennecka GL. High-Speed and High-Power Ferroelectric Switching Current Measurement Instrument for Materials with Large Coercive Voltage and Remanent Polarization. Sensors (Basel) 2022; 22:s22249659. [PMID: 36560028 PMCID: PMC9784202 DOI: 10.3390/s22249659] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 05/25/2023]
Abstract
A high-speed and high-power current measurement instrument is described for measuring rapid switching of ferroelectric samples with large spontaneous polarization and coercive field. Instrument capabilities (±200 V, 200 mA, and 200 ns order response) are validated with a LiTaO3 single crystal whose switching kinetics are well known. The new instrument described here enables measurements that are not possible using existing commercial measurement systems, including the observation of ferroelectric switching in large coercive field and large spontaneous polarization Al0.7Sc0.3N thin films.
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Affiliation(s)
- Keisuke Yazawa
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401, USA
- Materials Science Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Andriy Zakutayev
- Materials Science Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Geoff L. Brennecka
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401, USA
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5
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Burcea R, Barbot JF, Renault PO, Eyidi D, Girardeau T, Marteau M, Giovannelli F, Zenji A, Rampnoux JM, Dilhaire S, Eklund P, le Febvrier A. Influence of Generated Defects by Ar Implantation on the Thermoelectric Properties of ScN. ACS Appl Energy Mater 2022; 5:11025-11033. [PMID: 36185810 PMCID: PMC9516874 DOI: 10.1021/acsaem.2c01672] [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: 05/31/2022] [Accepted: 08/01/2022] [Indexed: 05/13/2023]
Abstract
Nowadays, making thermoelectric materials more efficient in energy conversion is still a challenge. In this work, to reduce the thermal conductivity and thus improve the overall thermoelectric performances, point and extended defects were generated in epitaxial 111-ScN thin films by implantation using argon ions. The films were investigated by structural, optical, electrical, and thermoelectric characterization methods. The results demonstrated that argon implantation leads to the formation of stable defects (up to 750 K operating temperature). These were identified as interstitial-type defect clusters and argon vacancy complexes. The insertion of these specific defects induces acceptor-type deep levels in the band gap, yielding a reduction in the free-carrier mobility. With a reduced electrical conductivity, the irradiated sample exhibited a higher Seebeck coefficient while maintaining the power factor of the film. The thermal conductivity is strongly reduced from 12 to 3 W·m-1·K-1 at 300 K, showing the influence of defects in increasing phonon scattering. Subsequent high-temperature annealing at 1573 K leads to the progressive evolution of these defects: the initial clusters of interstitials evolved to the benefit of smaller clusters and the formation of bubbles. Thus, the number of free carriers, the resistivity, and the Seebeck coefficient are almost restored but the mobility of the carriers remains low and a 30% drop in thermal conductivity is still effective (k total ∼ 8.5 W·m-1·K-1). This study shows that control defect engineering with defects introduced by irradiation using noble gases in a thermoelectric coating can be an attractive method to enhance the figure of merit of thermoelectric materials.
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Affiliation(s)
- Razvan Burcea
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Jean-François Barbot
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Pierre-Olivier Renault
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Dominique Eyidi
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Thierry Girardeau
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Marc Marteau
- Institute
PPRIME, CNRS, Université de Poitiers-ENSMA,
UPR 3346, SP2MI, TSA 41123, 86073 Poitiers cedex 9, France
| | - Fabien Giovannelli
- Laboratoire
GREMAN, CNRS, Université de Tours,
UMR 7347, 41029 Blois cedex, France
| | - Ahmad Zenji
- Laboratoire
LOMA, CNRS, Université de Bordeaux,
UMR 5798, 33405 Talence, France
| | | | - Stefan Dilhaire
- Laboratoire
LOMA, CNRS, Université de Bordeaux,
UMR 5798, 33405 Talence, France
| | - Per Eklund
- Department
of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
| | - Arnaud le Febvrier
- Department
of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
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6
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Wang B, Guo L, Zhang J, Qiao Y, He M, Jiang Q, Zhao Y, Shi X, Zhang F. Synthesis of Nickel Nitride-Based 1D/0D Heterostructure via a Morphology-Inherited Nitridation Strategy for Efficient Electrocatalytic Hydrogen Evolution. Small 2022; 18:e2201927. [PMID: 35595714 DOI: 10.1002/smll.202201927] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/02/2022] [Indexed: 06/15/2023]
Abstract
The fabrication of heterostructures has inspired extensive interest in promoting the performance of solar cells or solar fuel production, but it is still challenging for nitrides to prepare structurally ordered heterostructures. Herein, one nickel nitride-based heterostructure composed of 1D Ni0.2 Mo0.8 N nanorods and 0D Ni3 N nanoparticles (denoted as NiMoN/NiN) is reported to exhibit significantly promoted hydrogen evolution reaction performance in both alkaline and neutral media. In particular, the optimal overpotential of the NiMoN/NiN sample at 10 mA cm-2 in 1 m KOH is 49 mV. The successful fabrication of 1D/0D heterostructures is mainly ascribed to morphology-inherited nitridation of 1D oxide precursor (denoted as NiMoO-NRs) in situ grown on Ni foam surface, and attributed to strong Lewis acid-base interaction that renders the Ni2+ ions emitted from the oxide precursor to well coordinate with NH3 for the formation of Ni3 N nanoparticles during the nitridation process. It is theoretically and experimentally demonstrated that the special 1D/0D heterostructure provides tandem active phases Ni0.2 Mo0.8 N and Ni3 N for synergistic promotion in lowering the activation energy of H2 O dissociation and optimizing the adsorption energy of H, respectively. This work may open a new avenue for developing highly active tandem electrocatalysts for promising renewable energy conversion.
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Affiliation(s)
- Bin Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
- Center for Advanced Materials Research, School of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhongyuan Road 41, Zhengzhou, 450007, China
| | - Lingju Guo
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Zhongguancun Beiyitiao 11, Beijing, 100190, China
| | - Jiangwei Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
| | - Yuyan Qiao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
| | - Meng He
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Zhongguancun Beiyitiao 11, Beijing, 100190, China
| | - Qike Jiang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
| | - Yang Zhao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
| | - Xinghua Shi
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Zhongguancun Beiyitiao 11, Beijing, 100190, China
| | - Fuxiang Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China
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7
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Alig L, Eisenlohr KA, Zelenkova Y, Rosendahl S, Herbst-Irmer R, Demeshko S, Holthausen MC, Schneider S. Rhenium-Mediated Conversion of Dinitrogen and Nitric Oxide to Nitrous Oxide. Angew Chem Int Ed Engl 2021; 61:e202113340. [PMID: 34714956 PMCID: PMC9299976 DOI: 10.1002/anie.202113340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 10/01/2021] [Indexed: 11/28/2022]
Abstract
Reductive splitting of N2 is an attractive strategy towards nitrogen fixation beyond ammonia at ambient conditions. However, the resulting nitride complexes often suffer from thermodynamic overstabilization hampering functionalization. Furthermore, oxidative nitrogen atom transfer of N2 derived nitrides remains unknown. We here report a ReIV pincer platform that mediates N2 splitting upon chemical reduction or electrolysis with unprecedented yield. The N2 derived ReV nitrides undergo facile nitrogen atom transfer to nitric oxide, giving nitrous oxide nearly quantitatively. Experimental and computational results indicate that outer‐sphere ReN/NO radical coupling is facilitated by the activation of the nitride via initial coordination of NO.
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Affiliation(s)
- Lukas Alig
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Kim A Eisenlohr
- Goethe-Universität Frankfurt, Institut für Anorganische und Analytische Chemie, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany
| | - Yaroslava Zelenkova
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Sven Rosendahl
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Regine Herbst-Irmer
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Serhiy Demeshko
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Max C Holthausen
- Goethe-Universität Frankfurt, Institut für Anorganische und Analytische Chemie, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany
| | - Sven Schneider
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany
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8
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Schluschaß B, Borter JH, Rupp S, Demeshko S, Herwig C, Limberg C, Maciulis NA, Schneider J, Würtele C, Krewald V, Schwarzer D, Schneider S. Cyanate Formation via Photolytic Splitting of Dinitrogen. JACS Au 2021; 1:879-894. [PMID: 34240082 PMCID: PMC8243327 DOI: 10.1021/jacsau.1c00117] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Indexed: 05/05/2023]
Abstract
Light-driven N2 cleavage into molecular nitrides is an attractive strategy for synthetic nitrogen fixation. However, suitable platforms are rare. Furthermore, the development of catalytic protocols via this elementary step suffers from poor understanding of N-N photosplitting within dinitrogen complexes, as well as of the thermochemical and kinetic framework for coupled follow-up chemistry. We here present a tungsten pincer platform, which undergoes fully reversible, thermal N2 splitting and reverse nitride coupling, allowing for experimental derivation of thermodynamic and kinetic parameters of the N-N cleavage step. Selective N-N splitting was also obtained photolytically. DFT computations allocate the productive excitations within the {WNNW} core. Transient absorption spectroscopy shows ultrafast repopulation of the electronic ground state. Comparison with ground-state kinetics and resonance Raman data support a pathway for N-N photosplitting via a nonstatistically vibrationally excited ground state that benefits from vibronically coupled structural distortion of the core. Nitride carbonylation and release are demonstrated within a full synthetic cycle for trimethylsilylcyanate formation directly from N2 and CO.
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Affiliation(s)
- Bastian Schluschaß
- University
of Göttingen, Institute for Inorganic
Chemistry, Tammannstraße
4, 37077 Göttingen, Germany
| | - Jan-Hendrik Borter
- Department
of Dynamics at Surfaces, Max Planck Institute
for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Severine Rupp
- Theoretische
Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 4, 64287 Darmstadt, Germany
| | - Serhiy Demeshko
- University
of Göttingen, Institute for Inorganic
Chemistry, Tammannstraße
4, 37077 Göttingen, Germany
| | - Christian Herwig
- Institut
für Chemie, Humboldt Universität
zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Christian Limberg
- Institut
für Chemie, Humboldt Universität
zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Nicholas A. Maciulis
- Department
of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405-7102, United States
| | - Jessica Schneider
- University
of Göttingen, Institute for Inorganic
Chemistry, Tammannstraße
4, 37077 Göttingen, Germany
| | - Christian Würtele
- University
of Göttingen, Institute for Inorganic
Chemistry, Tammannstraße
4, 37077 Göttingen, Germany
| | - Vera Krewald
- Theoretische
Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 4, 64287 Darmstadt, Germany
| | - Dirk Schwarzer
- Department
of Dynamics at Surfaces, Max Planck Institute
for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Sven Schneider
- University
of Göttingen, Institute for Inorganic
Chemistry, Tammannstraße
4, 37077 Göttingen, Germany
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9
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Schiavon D, Litwin-Staszewska E, Jakieła R, Grzanka S, Perlin P. Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium. Materials (Basel) 2021; 14:ma14020354. [PMID: 33450822 PMCID: PMC7828268 DOI: 10.3390/ma14020354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 11/18/2022]
Abstract
The effect of growth temperature and precursor flow on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.
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Affiliation(s)
- Dario Schiavon
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
- Correspondence:
| | - Elżbieta Litwin-Staszewska
- Laboratory of Nitride Semiconductor Physics, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland;
| | - Rafał Jakieła
- Laboratory of X-ray and Electron Microscopy Research, Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland;
| | - Szymon Grzanka
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
| | - Piotr Perlin
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
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10
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Hirata K, Mori Y, Yamada H, Uehara M, Anggraini SA, Akiyama M. Significant Enhancement of Piezoelectric Response in AlN by Yb Addition. Materials (Basel) 2021; 14:E309. [PMID: 33435266 DOI: 10.3390/ma14020309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 11/17/2022]
Abstract
This study employs first-principles calculations to investigate how introducing Yb into aluminum nitride (AlN) leads to a large enhancement in the material's piezoelectric response (d33). The maximum d33 is calculated to be over 100 pC/N, which is 20 times higher than that of AlN. One reason for such a significant improvement in d33 is the elastic-softening effect, which is indicated by a decrease in the elastic constant, C33. The strain sensitivity (du/dε) of the internal parameter, u, is also an important factor for improving the piezoelectric stress constant, e33. On the basis of mixing enthalpy calculations, YbxAl1-xN is predicted to be more stable as a wurtzite phase than as a rock salt phase at composition up to x ≈ 0.7. These results suggest that Yb can be doped into AlN at high concentrations. It was also observed that the dielectric constant, ε33, generally increases with increasing Yb concentrations. However, the electromechanical coupling coefficient, k332, only increases up to x = 0.778, which is likely because of the relatively lower values of ε33 within this range.
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11
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O'Donovan M, Luisier M, O'Reilly EP, Schulz S. Impact of random alloy fluctuations on inter-well transport in InGaN/GaN multi-quantum well systems: an atomistic non-equilibrium Green's function study. J Phys Condens Matter 2020; 33:045302. [PMID: 32986018 DOI: 10.1088/1361-648x/abbbc6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
Recent experimental studies indicate the presence of ballistic hole transport in InGaN multi quantum well (MQW) structures. Widely used drift-diffusion models cannot give insight into this question, since quantum mechanical effects, such as tunneling, are not included in such semi-classical approaches. Also atomistic effects, e.g. carrier localization effects and built-in field variations due to (random) alloy fluctuations, are often neglected in ballistic transport calculations on InGaN quantum well systems. In this work we use atomistic tight-binding theory in conjunction with a non-equilibrium Green's function approach to study electron and hole ballistic transport in InGaN MQW systems. Our results show that for electrons the alloy microstructure is of secondary importance for their ballistic transport properties, while for hole transport the situation is different. We observe for narrow barrier widths in an InGaN MQW system that (random) alloy fluctuations give rise to extra hole transmission channels when compared to a virtual crystal description of the same system. We attribute this effect to the situation that in the random alloy case,k∥-vector conservation is broken/relaxed and therefore the ballistic hole transport is increased. However, for wider barrier width this effect is strongly reduced, which is consistent with experimental studies. Our findings also provide a possible explanation for recent experimental results where alloying the barrier between the wells leads to enhanced ballistic (hole) transport in InGaN MQW systems.
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Affiliation(s)
- Michael O'Donovan
- Tyndall National Institute, University College Cork, Cork, T12 R5CP, Ireland
- Department of Physics, University College Cork, Cork, T12 YN60, Ireland
| | - Mathieu Luisier
- Integrated Systems Laboratory, ETH Zürich, 8092 Zürich, Switzerland
| | - Eoin P O'Reilly
- Tyndall National Institute, University College Cork, Cork, T12 R5CP, Ireland
- Department of Physics, University College Cork, Cork, T12 YN60, Ireland
| | - Stefan Schulz
- Tyndall National Institute, University College Cork, Cork, T12 R5CP, Ireland
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12
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Nitta M, Nagao N, Nomura Y, Hirasawa T, Sakai Y, Ogata T, Azuma M, Torii S, Ishigaki T, Inada Y. High-Brightness Red-Emitting Phosphor La 3(Si,Al) 6(O,N) 11:Ce 3+ for Next-Generation Solid-State Light Sources. ACS Appl Mater Interfaces 2020; 12:31652-31658. [PMID: 32564587 DOI: 10.1021/acsami.0c09342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A novel high-brightness red-emitting phosphor, La3(Si,Al)6(O,N)11:Ce3+ (LSA), which can potentially be used as a laser-excited light source, is demonstrated. Laser-excited phosphor system has great potential for use as a white-light source, as it is orders of magnitude brighter than white LEDs. Although conventional yellow-green phosphors show excellent luminescent properties even under high-power laser excitation, red-emitting phosphors, which are essential to achieve a high color-rendering index and low color-temperature, show quantum efficiency quenching. This limits the output power in multiphosphor excitation systems. Ce3+ should successfully tolerate high-power excitation due to the shortest emission lifetime seen in rare-earth ions, caused by the 5d1-4f1 spin-allowed transition; however, a red-emitting Ce3+-doped phosphor of practical use has not been realized. LSA is described by the crystal-field modification of a yellow-emitting phosphor, La3Si6N11:Ce3+, with substitution of Al in Si sites. LSA shows 640 nm red emission together with tolerance for high-power excitation and thermal quenching, suggesting its significant potential for industrial applications that require ultrahigh brightness.
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Affiliation(s)
- Mitsuru Nitta
- Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan
- Engineering Division, Life Solutions Company, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8501, Japan
| | - Nobuaki Nagao
- Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan
| | - Yuki Nomura
- Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan
| | - Taku Hirasawa
- Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan
| | - Yuki Sakai
- Kanagawa Institute of Industrial Science and Technology, 705-1 Shimoimaizumi, Ebina, Kanagawa 243-0435, Japan
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - Takahiro Ogata
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Masaki Azuma
- Kanagawa Institute of Industrial Science and Technology, 705-1 Shimoimaizumi, Ebina, Kanagawa 243-0435, Japan
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Shuki Torii
- Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Toru Ishigaki
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, 162-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Yasuhisa Inada
- Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan
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13
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Abou Hamdan M, Nassereddine A, Checa R, Jahjah M, Pinel C, Piccolo L, Perret N. Supported Molybdenum Carbide and Nitride Catalysts for Carbon Dioxide Hydrogenation. Front Chem 2020; 8:452. [PMID: 32582635 PMCID: PMC7296157 DOI: 10.3389/fchem.2020.00452] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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: 04/02/2020] [Accepted: 04/30/2020] [Indexed: 12/19/2022] Open
Abstract
Catalysts based on molybdenum carbide or nitride nanoparticles (2-5 nm) supported on titania were prepared by wet impregnation followed by a thermal treatment under alkane (methane or ethane)/hydrogen or nitrogen/hydrogen mixture, respectively. The samples were characterized by elemental analysis, volumetric adsorption of nitrogen, X-ray diffraction, and aberration-corrected transmission electron microscopy. They were evaluated for the hydrogenation of CO2 in the 2-3 MPa and 200-300°C ranges using a gas-phase flow fixed bed reactor. CO, methane, methanol, and ethane (in fraction-decreasing order) were formed on carbides, whereas CO, methanol, and methane were formed on nitrides. The carbide and nitride phase stoichiometries were tuned by varying the preparation conditions, leading to C/Mo and N/Mo atomic ratios of 0.2-1.8 and 0.5-0.7, respectively. The carbide activity increased for lower carburizing alkane concentration and temperature, i.e., lower C/Mo ratio. Enhanced carbide performances were obtained with pure anatase titania support as compared to P25 (anatase/rutile) titania or zirconia, with a methanol selectivity up to 11% at 250°C. The nitride catalysts appeared less active but reached a methanol selectivity of 16% at 250°C.
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Affiliation(s)
- Marwa Abou Hamdan
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, France
| | | | - Ruben Checa
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, France
| | - Mohamad Jahjah
- LCIO, Laboratoire de Chimie de Coordination Inorganique et Organométallique, Université Libanaise- Faculté des Sciences I, Beyrouth, Lebanon
| | - Catherine Pinel
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, France
| | - Laurent Piccolo
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, France
| | - Noémie Perret
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, France
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14
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Chen L, Ran Y, Jiang Z, Li Y, Wang Z. Structural, Compositional, and Plasmonic Characteristics of Ti-Zr Ternary Nitride Thin Films Tuned by the Nitrogen Flow Ratio in Magnetron Sputtering. Nanomaterials (Basel) 2020; 10:E829. [PMID: 32349287 DOI: 10.3390/nano10050829] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/13/2020] [Accepted: 04/16/2020] [Indexed: 11/16/2022]
Abstract
Ternary nitride gives high diversity and tunability of the plasmonic materials. In this work, highly crystallized ternary (Ti, Zr)Nx films were prepared by magnetron co-sputtering with different nitrogen gas flow ratio Rn. The structural and plasmonic properties of the films tuned by Rn were investigated. All the films are solid solutions of TiNx and ZrNx with a rocksalt structure and (111) preferred orientation. The films are nitrogen-overstoichiometric and the main defects are cation vacancies. Increased Rn reduces the zirconium content, and therefore leads to the reduction of lattice constant and enhancement of the crystallinity. As Rn increases, the screened plasma frequency decreases for the reduction of free electron density. The maximum of the energy loss spectra of (Ti, Zr)Nx films shifts to long-wavelength with Rn increasing. The calculated electronic structure shows that increased nitrogen content enhances the electronic density of states of nitrogen and reduces that of metal, and therefore elevates the energy level at which interband transition is exited. The results show that (Ti, Zr)Nx films give a relatively high plasmonic quality in the visible and near-infrared region, and the film properties can be significantly tuned by the nitrogen content.
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15
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Zhang F, Jin L, Li H, Xie K. Coordinatively Unsaturated Metal-Nitrogen Active Sites at Twisted Surfaces in Metallic Porous Nitride Single Crystals Delivering Enhanced Electrocatalysis Activity. Chemistry 2020; 26:2327-2332. [PMID: 32012370 DOI: 10.1002/chem.201904423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 09/25/2019] [Revised: 11/04/2019] [Indexed: 11/11/2022]
Abstract
To create active sites on surfaces, the identification of structural features that could confine the local-defect structure in the lattice is required. Porous nitride single crystals, combining the advantages of porosity and structural coherence, provide the possibility to create coordinatively unsaturated metal-nitrogen active sites confined on surfaces. For the first time, ordered active sites and tailor the atomically resolved Fe-N and Co-N local structures are created through control of the unsaturated nitrogen coordination at twisted surfaces in porous single-crystalline Fen N (n=2-4) and Con N (n=1-3) nanocubes. The precise tailoring of the electronic structures of these coordinatively unsaturated active sites therefore engineer the catalytic activity. Optimum electrocatalysis performances are observed with the porous Fe4 N and Co3 N nanocubes with highly unsaturated nitrogen coordination for selective nitrate reduction to ammonia and nitrobenzene amination to aminobenzene, while the structural coherence of these porous nitride single crystals delivers excellent durability.
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Affiliation(s)
- Feiyan Zhang
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Lu Jin
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Hao Li
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Kui Xie
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
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16
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Dong B, Cui J, Gao Y, Qi Y, Zhang F, Li C. Heterostructure of 1D Ta 3 N 5 Nanorod/BaTaO 2 N Nanoparticle Fabricated by a One-Step Ammonia Thermal Route for Remarkably Promoted Solar Hydrogen Production. Adv Mater 2019; 31:e1808185. [PMID: 30785220 DOI: 10.1002/adma.201808185] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Heterostructures are widely fabricated for promotion of photogenerated charge separation and solar cell/fuel production. (Oxy)nitrides are extremely promising for solar energy conversion, but the fabrication of heterostructures based on nitrogen-containing semiconductors is still challenging. Here, a simple ammonia thermal synthesis of a heterostructure (denoted as Ta3 N5 /BTON) composed of 1D Ta3 N5 nanorods and BaTaO2 N (BTON) nanoparticles (0D), which is demonstrated to result in a remarkable increase in photogenerated charge separation and solar hydrogen production from water, is introduced. As analyzed and discussed, the Ta3 N5 /BTON heterostructure is type II and tends to create intimate interfaces between the 1D nanorods and 0D nanoparticles. The 1D Ta3 N5 nanorods are demonstrated to transfer electrons along the rod orientation direction. Furthermore, the intimate interfaces of the heterostructure are believed to originate from the similar Ta-based octahedron units of Ta3 N5 and BTON. All of the above features are expected to integrally endow increased photoinduced charge separation and one order of magnitude higher solar overall water splitting activity with respect to counterpart systems. These results may open a new avenue to fabricate heterostructures on the basis of nitrogen-containing semiconductors that is extremely promising for solar energy conversion.
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Affiliation(s)
- Beibei Dong
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junyan Cui
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
| | - Yuying Gao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yu Qi
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
| | - Fuxiang Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
| | - Can Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian, 116023, China
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17
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Griffin P, Zhu T, Oliver R. Porous AlGaN-Based Ultraviolet Distributed Bragg Reflectors. Materials (Basel) 2018; 11:E1487. [PMID: 30134525 DOI: 10.3390/ma11091487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/14/2018] [Accepted: 08/16/2018] [Indexed: 11/20/2022]
Abstract
Utilising dislocation-related vertical etching channels in gallium nitride, we have previously demonstrated a simple electrochemical etching (ECE) process that can create layered porous GaN structures to form distributed Bragg reflectors for visible light at wafer scale. Here, we apply the same ECE process to realise AlGaN-based ultraviolet distributed Bragg reflectors (DBRs). These are of interest because they could provide a pathway to non-absorbing UV reflectors to enhance the performance of UV LEDs, which currently have extremely low efficiency. We have demonstrated porous AlGaN-based UV DBRs with a peak reflectance of 89% at 324 nm. The uniformity of these devices is currently low, as the as-grown material has a high density of V-pits and these alter the etching process. However, our results indicate that if the material growth is optimised, the ECE process will be useful for the fabrication of UV reflectors.
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18
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Liu WQ, Wu D, Chang H, Duan RX, Wu WJ, Amu G, Chao KF, Bao FQ, Tegus O. The Enhanced Red Emission and Improved Thermal Stability of CaAlSiN₃:Eu 2+ Phosphors by Using Nano-EuB₆ as Raw Material. Nanomaterials (Basel) 2018; 8:E66. [PMID: 29370148 PMCID: PMC5853698 DOI: 10.3390/nano8020066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/19/2018] [Accepted: 01/22/2018] [Indexed: 11/18/2022]
Abstract
Synthesizing phosphors with high performance is still a necessary work for phosphor-converted white light-emitting diodes (W-LEDs). In this paper, three series of CaAlSiN₃:Eu2+ (denoted as CASN:Eu2+) phosphors using Eu₂O₃, EuN and EuB₆ as raw materials respectively are fabricated by under the alloy precursor normal pressure nitridation synthesis condition. We demonstrate that CASN:Eu2+ using nano-EuB₆ as raw material shows higher emission intensity than others, which is ascribed to the increment of Eu2+ ionic content entering into the crystal lattice. An improved thermal stability can also be obtained by using nano-EuB₆ due to the structurally stable status, which is assigned to the partial substitution of Eu-O (Eu-N) bonds by more covalent Eu-B ones that leads to a higher structural rigidity. In addition, the W-LEDs lamp was fabricated to explore its possible application in W-LEDs based on blue LEDs. Our results indicate that using EuB₆ as raw materials can provide an effective way of enhancing the red emission and improving the thermal stability of the CASN:Eu2+ red phosphor.
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Affiliation(s)
- Wen-Quan Liu
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Dan Wu
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, China;
| | - Hugejile Chang
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Ru-Xia Duan
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Wen-Jie Wu
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Guleng Amu
- Department of physics and electrical engineering, Xilingol Vocational College, Xilinhot 0026000, China;
| | - Ke-Fu Chao
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Fu-Quan Bao
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
| | - Ojiyed Tegus
- Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China; (W.-Q.L.); (H.C.); (R.-X.D.); (W.-J.W.); (F.-Q.B.)
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19
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Little DJ, Edwards DO, Smith MR, Hamann TW. As Precious as Platinum: Iron Nitride for Electrocatalytic Oxidation of Liquid Ammonia. ACS Appl Mater Interfaces 2017; 9:16228-16235. [PMID: 28447778 DOI: 10.1021/acsami.7b02639] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [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
The electrolysis of ammonia (NH3), a potential carrier for hydrogen fuel, has only been studied in detail in systems employing expensive, noble metal anodes such as platinum, ruthenium, and iridium. For NH3 to serve as a practical hydrogen storage medium, the electrolysis process must be energy efficient, scalable, and inexpensive. Clearly, alternatives to precious metals would greatly reduce costs if the performance of less expensive, more abundant metals rivaled those of their expensive counterparts. In this regard, no metal is less expensive than iron. Iron exhibits complex anodic behavior in liquid ammonia (NH3(l)), with a high sensitivity to trace amounts of dissolved water, and a tendency to corrosively dissolve with appropriate applied bias. However, with sufficient applied overpotential in distilled NH3(l), an iron nitride film forms in situ that is resistant to dissolution. On this in situ-modified surface, dinitrogen evolution out-performs anodic dissolution with an efficiency of over 95%. Amazingly, the onset potential for dinitrogen evolution in NH3(l) on this in situ-modified iron surface is almost identical to what is measured on a platinum electrode.
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Affiliation(s)
- Daniel J Little
- Department of Chemistry, Michigan State University , 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Dillon O Edwards
- Department of Chemistry, Michigan State University , 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Milton R Smith
- Department of Chemistry, Michigan State University , 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Thomas W Hamann
- Department of Chemistry, Michigan State University , 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
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20
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Cleaves PA, Kefalidis CE, Gardner BM, Tuna F, McInnes EJL, Lewis W, Maron L, Liddle ST. Terminal Uranium(V/VI) Nitride Activation of Carbon Dioxide and Carbon Disulfide: Factors Governing Diverse and Well-Defined Cleavage and Redox Reactions. Chemistry 2017; 23:2950-2959. [PMID: 28075505 DOI: 10.1002/chem.201605620] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [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: 12/01/2016] [Indexed: 01/22/2023]
Abstract
The reactivity of terminal uranium(V/VI) nitrides with CE2 (E=O, S) is presented. Well-defined C=E cleavage followed by zero-, one-, and two-electron redox events is observed. The uranium(V) nitride [U(TrenTIPS )(N)][K(B15C5)2 ] (1, TrenTIPS =N(CH2 CH2 NSiiPr3 )3 ; B15C5=benzo-15-crown-5) reacts with CO2 to give [U(TrenTIPS )(O)(NCO)][K(B15C5)2 ] (3), whereas the uranium(VI) nitride [U(TrenTIPS )(N)] (2) reacts with CO2 to give isolable [U(TrenTIPS )(O)(NCO)] (4); complex 4 rapidly decomposes to known [U(TrenTIPS )(O)] (5) with concomitant formation of N2 and CO proposed, with the latter trapped as a vanadocene adduct. In contrast, 1 reacts with CS2 to give [U(TrenTIPS )(κ2 -CS3 )][K(B15C5)2 ] (6), 2, and [K(B15C5)2 ][NCS] (7), whereas 2 reacts with CS2 to give [U(TrenTIPS )(NCS)] (8) and "S", with the latter trapped as Ph3 PS. Calculated reaction profiles reveal outer-sphere reactivity for uranium(V) but inner-sphere mechanisms for uranium(VI); despite the wide divergence of products the initial activation of CE2 follows mechanistically related pathways, providing insight into the factors of uranium oxidation state, chalcogen, and NCE groups that govern the subsequent divergent redox reactions that include common one-electron reactions and a less-common two-electron redox event. Caution, we suggest, is warranted when utilising CS2 as a reactivity surrogate for CO2 .
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Affiliation(s)
- Peter A Cleaves
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Christos E Kefalidis
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, Toulouse, 31077, France
| | - Benedict M Gardner
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Floriana Tuna
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Eric J L McInnes
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - William Lewis
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Laurent Maron
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, Toulouse, 31077, France
| | - Stephen T Liddle
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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21
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Liu ZTY, Burton BP, Khare SV, Gall D. First-principles phase diagram calculations for the rocksalt-structure quasibinary systems TiN-ZrN, TiN-HfN and ZrN-HfN. J Phys Condens Matter 2017; 29:035401. [PMID: 27845927 PMCID: PMC5508868 DOI: 10.1088/0953-8984/29/3/035401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have studied the phase equilibria of three ceramic quasibinary systems Ti1-x Zr x N, Ti1-x Hf x N and Zr1-x Hf x N (0 ⩽ x ⩽ 1) with density functional theory, cluster expansion and Monte Carlo simulations. We predict consolute temperatures (T C), at which miscibility gaps close, for Ti1-x Zr x N to be 1400 K, for Ti1-x Hf x N to be 700 K, and below 200 K for Zr1-x Hf x N. The asymmetry of the formation energy ΔE f(x) is greater for Ti1-x Hf x N than Ti1-x Zr x N, with less solubility on the smaller cation TiN-side, and similar asymmetries were predicted for the corresponding phase diagrams. We also analyzed different energetic contributions: ΔE f of the random solid solutions were decomposed into a volume change term, [Formula: see text], and a chemical exchange and relaxation term, [Formula: see text]. These two energies partially cancel one another. We conclude that [Formula: see text] influences the magnitude of T C and [Formula: see text] influences the asymmetry of ΔE f(x) and phase boundaries. We also conclude that the absence of experimentally observed phase separation in Ti1-x Zr x N and Ti1-x Hf x N is due to slow kinetics at low temperatures. In addition, elastic constants and mechanical properties of the random solid solutions were studied with the special quasirandom solution approach. Monotonic trends, in the composition dependence, of shear-related mechanical properties, such as Vickers hardness between 18 to 23 GPa, were predicted. Trends for Ti1-x Zr x N and Ti1-x Hf x N exhibit down-bowing (convexity). It shows that mixing nitrides of same group transition metals does not lead to hardness increase from an electronic origin, but through solution hardening mechanism. The mixed thin films show consistency and stability with little phase separation, making them desirable coating choices.
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Affiliation(s)
- Z T Y Liu
- Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606, USA
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22
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Wang L, Xie RJ, Li Y, Wang X, Ma CG, Luo D, Takeda T, Tsai YT, Liu RS, Hirosaki N. Ca 1-x Li x Al 1-x Si 1+x N 3:Eu 2+ solid solutions as broadband, color-tunable and thermally robust red phosphors for superior color rendition white light-emitting diodes. Light Sci Appl 2016; 5:e16155. [PMID: 30167122 PMCID: PMC6059829 DOI: 10.1038/lsa.2016.155] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 05/08/2023]
Abstract
Color rendition, luminous efficacy and reliability are three key technical parameters for white light-emitting diodes (wLEDs) that are dominantly determined by down-conversion phosphors. However, there is usually an inevitable trade-off between color rendition and luminescence efficacy because the spectrum of red phosphor (that is, spectral broadness and position) cannot satisfy them simultaneously. In this work, we report a very promising red phosphor that can minimize the aforementioned trade-off via structure and band-gap engineering, achieved by introducing isostructural LiSi2N3 into CaAlSiN3:Eu2+. The solid solution phosphors show both substantial spectra broadening (88→117 nm) and blueshift (652→642 nm), along with a significant improvement in thermal quenching (only a 6% reduction at 150 °C), which are strongly associated with electronic and crystal structure evolutions. The broadband and robust red phosphor thus enables fabrication of super-high color rendering wLEDs (Ra=95 and R9=96) concurrently with the maintenance of a high-luminous efficacy (101 lm W-1), validating its superiority in high-performance solid state lightings over currently used red phosphors.
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Affiliation(s)
- Le Wang
- College of Optics and Electronic Science and Technology, China Jiliang University, Hangzhou, Zhejiang 310018, China
| | - Rong-Jun Xie
- College of Materials, Xiamen University, Xiamen, Fujian 361005, China
- Sialon Group, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | | | - Xiaojun Wang
- Sialon Group, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Chong-Geng Ma
- College of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Dong Luo
- College of Optics and Electronic Science and Technology, China Jiliang University, Hangzhou, Zhejiang 310018, China
| | - Takashi Takeda
- Sialon Group, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | | | - Ru-Shi Liu
- Department of Chemistry, Taiwan University
- Department of Mechanical Engineering and Graduate Institute of Manufacturing Technology, Taipei University of Technology
| | - Naoto Hirosaki
- Sialon Group, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
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23
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Xu SM, Zhu QC, Harris M, Chen TH, Ma C, Wei X, Xu HS, Zhou YX, Cao YC, Wang KX, Chen JS. Toward Lower Overpotential through Improved Electron Transport Property: Hierarchically Porous CoN Nanorods Prepared by Nitridation for Lithium-Oxygen Batteries. Nano Lett 2016; 16:5902-5908. [PMID: 27504675 DOI: 10.1021/acs.nanolett.6b02805] [Citation(s) in RCA: 11] [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] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
To lower the overpotential of a lithium-oxygen battery, electron transport at the solid-to-solid interface between the discharge product Li2O2 and the cathode catalyst is of great significance. Here we propose a strategy to enhance electron transport property of the cathode catalyst by the replace of oxygen atoms in the generally used metal oxide-based catalysts with nitrogen atoms to improve electron density at Fermi energy after nitridation. Hierarchically porous CoN nanorods were obtained by thermal treatment of Co3O4 nanorods under ammonia atmosphere at 350 °C. Compared with that of the pristine Co3O4 precursor before nitridation, the overpotential of the obtained CoN cathode was significantly decreased. Moreover, specific capacity and cycling stability of the CoN nanorods were enhanced. It is assumed that the discharged products with different morphologies for Co3O4 and CoN cathodes might be closely associated with the variation in the electronic density induced by occupancy of nitrogen atoms into interstitial sites of metal lattice after nitridation. The nitridation strategy for improved electron density proposed in this work is proved to be a simple but efficient way to improve the electrochemical performance of metal oxide based cathodes for lithium-oxygen batteries.
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Affiliation(s)
- Shu-Mao Xu
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Qian-Cheng Zhu
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Michelle Harris
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Tong-Heng Chen
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Chao Ma
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Xiao Wei
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | | | | | | | - Kai-Xue Wang
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
| | - Jie-Sheng Chen
- Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
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24
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Schendzielorz FS, Finger M, Volkmann C, Würtele C, Schneider S. A Terminal Osmium(IV) Nitride: Ammonia Formation and Ambiphilic Reactivity. Angew Chem Int Ed Engl 2016; 55:11417-20. [PMID: 27529412 DOI: 10.1002/anie.201604917] [Citation(s) in RCA: 56] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/06/2016] [Indexed: 11/08/2022]
Abstract
Low-valent osmium nitrides are discussed as intermediates in nitrogen fixation schemes. However, rational synthetic routes that lead to isolable examples are currently unknown. Here, the synthesis of the square-planar osmium(IV) nitride [OsN(PNP)] (PNP=N(CH2 CH2 P(tBu)2 )2 ) is reported upon reversible deprotonation of osmium(VI) hydride [Os(N)H(PNP)](+) . The Os(IV) complex shows ambiphilic nitride reactivity with SiMe3 Br and PMe3 , respectively. Importantly, the hydrogenolysis with H2 gives ammonia and the polyhydride complex [OsH4 (HPNP)] in 80 % yield. Hence, our results directly demonstrate the role of low-valent osmium nitrides and of heterolytic H2 activation for ammonia synthesis with H2 under basic conditions.
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Affiliation(s)
- Florian S Schendzielorz
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 1, 37077, Göttingen, Germany
| | - Markus Finger
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 1, 37077, Göttingen, Germany
| | - Christian Volkmann
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 1, 37077, Göttingen, Germany
| | - Christian Würtele
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 1, 37077, Göttingen, Germany
| | - Sven Schneider
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 1, 37077, Göttingen, Germany.
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25
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Qu F, Yuan Y, Guarecuco R, Yang M. Low Working-Temperature Acetone Vapor Sensor Based on Zinc Nitride and Oxide Hybrid Composites. Small 2016; 12:3128-33. [PMID: 27145332 DOI: 10.1002/smll.201600422] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [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: 02/08/2016] [Revised: 03/21/2016] [Indexed: 05/27/2023]
Abstract
Transition-metal nitride and oxide composites are a significant class of emerging materials that have attracted great interest for their potential in combining the advantages of nitrides and oxides. Here, a novel class of gas sensing materials based on hybrid Zn3 N2 and ZnO composites is presented. The Zn3 N2 /ZnO (ZnNO) composites-based sensor exhibits selectivity and high sensitivity toward acetone vapor, and the sensitivity is dependent on the nitrogen content of the composites. The ZnNO-11.7 described herein possesses a low working temperature of 200 °C. The detection limit (0.07 ppm) is below the diabetes diagnosis threshold (1.8 ppm). In addition, the sensor shows high reproducibility and long-term stability.
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Affiliation(s)
- Fengdong Qu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Yao Yuan
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Rohiverth Guarecuco
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
| | - Minghui Yang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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26
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Guan N, Dai X, Messanvi A, Zhang H, Yan J, Gautier E, Bougerol C, Julien F, Durand C, Eymery J, Tchernycheva M. Flexible White Light Emitting Diodes Based on Nitride Nanowires and Nanophosphors. ACS Photonics 2016; 3:597-603. [PMID: 27331079 PMCID: PMC4902128 DOI: 10.1021/acsphotonics.5b00696] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Indexed: 05/17/2023]
Abstract
We report the first demonstration of flexible white phosphor-converted light emitting diodes (LEDs) based on p-n junction core/shell nitride nanowires. GaN nanowires containing seven radial In0.2Ga0.8N/GaN quantum wells were grown by metal-organic chemical vapor deposition on a sapphire substrate by a catalyst-free approach. To fabricate the flexible LED, the nanowires are embedded into a phosphor-doped polymer matrix, peeled off from the growth substrate, and contacted using a flexible and transparent silver nanowire mesh. The electroluminescence of a flexible device presents a cool-white color with a spectral distribution covering a broad spectral range from 400 to 700 nm. Mechanical bending stress down to a curvature radius of 5 mm does not yield any degradation of the LED performance. The maximal measured external quantum efficiency of the white LED is 9.3%, and the wall plug efficiency is 2.4%.
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Affiliation(s)
- Nan Guan
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
| | - Xing Dai
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
| | - Agnès Messanvi
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
- Université
Grenoble Alpes, 38000 Grenoble, France
- “Nanophysique
et Semiconducteurs” Group, CEA, INAC-SP2M, 17 Rue des Martyrs, 38000 Grenoble, France
| | - Hezhi Zhang
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
| | - Jianchang Yan
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
- Institute
of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
| | - Eric Gautier
- Université
Grenoble Alpes, 38000 Grenoble, France
- CEA,
INAC-SPINTEC, 17 Rue
des Martyrs, 38000 Grenoble, France
| | - Catherine Bougerol
- Université
Grenoble Alpes, 38000 Grenoble, France
- “Nanophysique
et Semiconducteurs” Group, CNRS, Institut Néel, 25 Rue des Martyrs, 38000 Grenoble, France
| | - François
H. Julien
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
| | - Christophe Durand
- Université
Grenoble Alpes, 38000 Grenoble, France
- “Nanophysique
et Semiconducteurs” Group, CEA, INAC-SP2M, 17 Rue des Martyrs, 38000 Grenoble, France
| | - Joël Eymery
- Université
Grenoble Alpes, 38000 Grenoble, France
- “Nanophysique
et Semiconducteurs” Group, CEA, INAC-SP2M, 17 Rue des Martyrs, 38000 Grenoble, France
- E-mail:
| | - Maria Tchernycheva
- Institut
d’Electronique Fondamentale, UMR 8622 CNRS, Université
Paris Saclay, 91405 Orsay, France
- E-mail:
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27
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Das D, Shinde SL, Nanda KK. Temperature-Dependent Photoluminescence of g-C3N4: Implication for Temperature Sensing. ACS Appl Mater Interfaces 2016; 8:2181-6. [PMID: 26714053 DOI: 10.1021/acsami.5b10770] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report the temperature-dependent photoluminescence (PL) properties of polymeric graphite-like carbon nitride (g-C3N4) and a methodology for the determination of quantum efficiency along with the activation energy. The PL is shown to originate from three different pathways of transitions: σ*-LP, π*-LP, and π*-π, respectively. The overall activation energy is found to be ∼73.58 meV which is much lower than the exciton binding energy reported theoretically but ideal for highly sensitive wide-range temperature sensing. The quantum yield derived from the PL data is 23.3%, whereas the absolute quantum yield is 5.3%. We propose that the temperature-dependent PL can be exploited for the evaluation of the temperature dependency of quantum yield as well as for temperature sensing. Our analysis further indicates that g-C3N4 is well-suited for wide-range temperature sensing.
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Affiliation(s)
- Debanjan Das
- Materials Research Centre, Indian Institute of Science , Bangalore 560012, India
| | - S L Shinde
- Materials Research Centre, Indian Institute of Science , Bangalore 560012, India
| | - K K Nanda
- Materials Research Centre, Indian Institute of Science , Bangalore 560012, India
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28
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Shields MR, Guzei IA, Goll JG. Crystal structure of nitrido[5,10,15,20-tetra-kis(4-methylphenyl)-porphyrinato]-manganese(V). Acta Crystallogr Sect E Struct Rep Online 2014; 70:242-5. [PMID: 25484663 PMCID: PMC4257217 DOI: 10.1107/s1600536814020558] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/13/2014] [Indexed: 12/04/2022]
Abstract
The title compound, [Mn(C48H36N4)(N)], is a manganese(V) complex with the transition metal in a square-pyramidal coordination geometry and a nitride as the axial ligand. The complex resides on a crystallographic inversion center and only one half of it is symmetry independent. The Mn(V) atom and the nitride N atom are equally disordered across the inversion center. The Mn N distance is 1.516 (4) Å. The Mn(V) atom is displaced from the plane defined by the four equatorial nitro-gen atoms toward the nitride ligand by 0.3162 (6) Å.
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Affiliation(s)
- Mason R. Shields
- Department of Chemistry, Geoscience, and Physics, 1000 Edgewood College Drive, Edgewood College, Madison, WI 53711, USA
| | - Ilia A. Guzei
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI 53706, USA
| | - James G. Goll
- Department of Chemistry, Geoscience, and Physics, 1000 Edgewood College Drive, Edgewood College, Madison, WI 53711, USA
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29
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Chan KW, Tjong SC. Effect of Secondary Phase Precipitation on the Corrosion Behavior of Duplex Stainless Steels. Materials (Basel) 2014; 7:5268-304. [PMID: 28788129 DOI: 10.3390/ma7075268] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 07/02/2014] [Accepted: 07/11/2014] [Indexed: 11/22/2022]
Abstract
Duplex stainless steels (DSSs) with austenitic and ferritic phases have been increasingly used for many industrial applications due to their good mechanical properties and corrosion resistance in acidic, caustic and marine environments. However, DSSs are susceptible to intergranular, pitting and stress corrosion in corrosive environments due to the formation of secondary phases. Such phases are induced in DSSs during the fabrication, improper heat treatment, welding process and prolonged exposure to high temperatures during their service lives. These include the precipitation of sigma and chi phases at 700–900 °C and spinodal decomposition of ferritic grains into Cr-rich and Cr-poor phases at 350–550 °C, respectively. This article gives the state-of the-art review on the microstructural evolution of secondary phase formation and their effects on the corrosion behavior of DSSs.
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30
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Tapia-Ruiz N, Sorbie N, Vaché N, Hoang TKA, Gregory DH. Rapid Microwave Synthesis, Characterization and Reactivity of Lithium Nitride Hydride, Li₄NH. Materials (Basel) 2013; 6:5410-5426. [PMID: 28788398 PMCID: PMC5452770 DOI: 10.3390/ma6115410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 10/23/2013] [Accepted: 11/11/2013] [Indexed: 10/27/2022]
Abstract
Lithium nitride hydride, Li₄NH, was synthesised from lithium nitride and lithium hydride over minute timescales, using microwave synthesis methods in the solid state for the first time. The structure of the microwave-synthesised powders was confirmed by powder X-ray diffraction [tetragonal space group I4₁/a; a = 4.8864(1) Å, c = 9.9183(2) Å] and the nitride hydride reacts with moist air under ambient conditions to produce lithium hydroxide and subsequently lithium carbonate. Li₄NH undergoes no dehydrogenation or decomposition [under Ar(g)] below 773 K. A tetragonal-cubic phase transition, however, occurs for the compound at ca. 770 K. The new high temperature (HT) phase adopts an anti-fluorite structure (space group Fm 3̅ m; a = 4.9462(3) Å) with N3- and H- ions disordered on the 4a sites. Thermal treatment of Li₄NH under nitrogen yields a stoichiometric mixture of lithium nitride and lithium imide (Li₃N and Li₂NH respectively).
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Affiliation(s)
- Nuria Tapia-Ruiz
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Natalie Sorbie
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Nicolas Vaché
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
- Ecole Nationale Supérieure de Chimie de Clermont-Ferrand, Université Blaise Pascal, BP 187, Aubière Cedex 63174, France.
| | - Tuan K A Hoang
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Duncan H Gregory
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
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31
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Yang YS, Cho TP. Effect of Annealing Temperature on the Water Contact Angle of PVD Hard Coatings. Materials (Basel) 2013; 6:3373-86. [PMID: 28811440 DOI: 10.3390/ma6083373] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 07/26/2013] [Accepted: 08/02/2013] [Indexed: 11/17/2022]
Abstract
Various PVD (physical vapor deposition) hard coatings including nitrides and metal-doped diamond-like carbons (Me-DLC) were applied in plastic injection and die-casting molds to improve wear resistance and reduce sticking. In this study, nitrides hcp-AlN (hexagonal close-packed AlN), Cr₂N, (CrAl)₂N) and Me-DLC (Si-DLC and Cr-DLC) coatings were prepared using a closed field unbalanced magnetron reactive sputtering system. The coatings were annealed in air for 2 h at various temperatures, after which the anti-sticking properties were assessed using water contact angle (WCA) measurements. The as-deposited hcp-AlN, Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior and exhibit respective WCAs of 119°, 106° and 101°. The as-deposited Si-DLC and Cr-DLC coatings exhibit hydrophilic behavior and exhibit respective WCAs of 74° and 88°. The annealed Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior with higher WCAs, while the annealed hcp-AlN, Si-DLC and Cr-DLC coatings are hydrophilic. The increased WCA of the annealed Cr₂N and (CrAl)₂N coatings is related to their crystal structure and increased roughness. The decreased WCA of the annealed hcp-AlN, Si-DLC and Cr-DLC coatings is related to their crystal structures and has little correlation with roughness.
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32
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Friedrich A, Winkler B, Juarez-Arellano EA, Bayarjargal L. Synthesis of Binary Transition Metal Nitrides, Carbides and Borides from the Elements in the Laser-Heated Diamond Anvil Cell and Their Structure-Property Relations. Materials (Basel) 2011; 4:1648-92. [PMID: 28824101 DOI: 10.3390/ma4101648] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 09/13/2011] [Accepted: 09/16/2011] [Indexed: 11/23/2022]
Abstract
Transition metal nitrides, carbides and borides have a high potential for industrial applications as they not only have a high melting point but are generally harder and less compressible than the pure metals. Here we summarize recent advances in the synthesis of binary transition metal nitrides, carbides and borides focusing on the reaction of the elements at extreme conditions generated within the laser-heated diamond anvil cell. The current knowledge of their structures and high-pressure properties like high-(p,T) stability, compressibility and hardness is described as obtained from experiments.
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33
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Lowther JE. The Role Played by Computation in Understanding Hard Materials. Materials (Basel) 2011; 4:1104-1116. [PMID: 28879969 PMCID: PMC5448642 DOI: 10.3390/ma4061104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/02/2011] [Accepted: 06/08/2011] [Indexed: 11/16/2022]
Abstract
In the last decade, computation has played a valuable role in the understanding of materials. Hard materials, in particular, are only part of the application. Although materials involving B, C, N or O remain the most valued atomic component of hard materials, with diamond retaining its distinct superiority as the hardest, other materials involving a wide variety of metals are proving important. In the present work the importance of both ab-initio approaches and molecular dynamics aspects will be discussed with application to quite different systems. On one hand, ab-initio methods are applied to lightweight systems and advanced nitrides. Following, the use of molecular dynamics will be considered with application to strong metals that are used for high temperature applications.
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Affiliation(s)
- John Edward Lowther
- DST/NRF Centre of Excellence in Strong Materials and School of Physics, University of the Witwatersrand, Johannesburg 2094, South Africa.
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