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Advantageous Interfacial Effects of AgPd/g-C3N4 for Photocatalytic Hydrogen Evolution: Electronic Structure and H2O Dissociation |
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| Authors: | Dr Weixin Zou Lixia Xu Yu Pu Haojie Cai Xiaoqian Wei Yidan Luo Dr Lulu Li Prof Dr Bin Gao Prof Dr Haiqin Wan Prof Dr Lin Dong |
| Institution: | 1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 PR China
Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093 PR China Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing, 210093 PR China;2. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 PR China Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing, 210093 PR China;3. Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093 PR China Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing, 210093 PR China;4. Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 32611 USA;5. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093 PR China |
| Abstract: | Bimetallic AgPd nanoparticles have been synthesized before, but the interfacial electronic effects of AgPd on the photocatalytic performance have been investigated less. In this work, the results of hydrogen evolution suggest that the bimetallic AgPd/g-C3N4 sample has superior activity to Ag/g-C3N4 and Pd/g-C3N4 photocatalysts. The UV/Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, CO adsorption diffuse reflectance FTIR spectroscopy, and FTIR results demonstrate that in the AgPd/g-C3N4, the surface electronic structures of Pd and Ag are changed, which is beneficial for faster photogenerated electron transfer and greater H2O molecule adsorption. In situ ESR spectra suggest that, under visible light irradiation, there is more H2O dissociation to radical species on the AgPd/g-C3N4 photocatalyst. Furthermore, DFT calculations confirm the interfacial electronic effects of AgPd/g-C3N4, that is, Pdδ−⋅⋅⋅Agδ+, and the activation energy of H2O molecule dissociation on AgPd/g-C3N4 is the lowest, which is the main contributor to the enhanced photocatalytic H2 evolution. |
| Keywords: | AgPd/g-C3N4 bimetallic interfacial electronic effect nanoparticles photocatalytic hydrogen evolution water splitting |