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Self-Optimization of the Active Site of Molybdenum Disulfide by an Irreversible Phase Transition during Photocatalytic Hydrogen Evolution |
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| Authors: | Longlu Wang Xia Liu Jinming Luo Xidong Duan Prof John Crittenden Prof Chengbin Liu Shuqu Zhang Prof Yong Pei Yunxiong Zeng Prof Xiangfeng Duan |
| Institution: | 1. State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 P.R. China
These authors contributed equally to this work.;2. Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, Xiangtan, 411105 P.R. China These authors contributed equally to this work.;3. Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 3, 0332 USA These authors contributed equally to this work.;4. Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 3, 0332 USA;5. State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 P.R. China;6. Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, Xiangtan, 411105 P.R. China;7. Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095 USA |
| Abstract: | The metallic 1T-MoS2 has attracted considerable attention as an effective catalyst for hydrogen evolution reactions (HERs). However, the fundamental mechanism about the catalytic activity of 1T-MoS2 and the associated phase evolution remain elusive and controversial. Herein, we prepared the most stable 1T-MoS2 by hydrothermal exfoliation of MoS2 nanosheets vertically rooted into rigid one-dimensional TiO2 nanofibers. The 1T-MoS2 can keep highly stable over one year, presenting an ideal model system for investigating the HER catalytic activities as a function of the phase evolution. Both experimental studies and theoretical calculations suggest that 1T phase can be irreversibly transformed into a more active 1T′ phase as true active sites in photocatalytic HERs, resulting in a “catalytic site self-optimization”. Hydrogen atom adsorption is the major driving force for this phase transition. |
| Keywords: | ab initio calculations molybdenum disulfide monolayers phase transitions photocatalysis |