Understanding Boosted Selective CO2-to-CO Photoreduction with Pure Water Vapor over Hierarchical Biomass-Derived Carbon Matrix |
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Authors: | Zhifeng Jiang Zhiquan Zhang Jianli Liang Min Zhou Daobin Liu Danjun Mao Qun Zhang Wei Zhang Huaming Li Li Song Taicheng An Po Keung Wong Chun-Sing Lee |
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Affiliation: | 1. Institute for Energy Research, Jiangsu University, Zhenjiang, 212013 China;2. Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of, Hong Kong, Hong Kong SAR, 999077 China;3. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029 China;4. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023 China;5. Department of Chemical Physics, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China;6. Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006 China |
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Abstract: | Solar-driven CO2 reduction reaction (CO2RR) with water into carbon-neutral fuels is of great significance but remains challenging due to thermodynamic stability and kinetic inertness of CO2. Biomass-derived nitrogen-doped carbon (N-Cb) have been considered as promising earth-abundant photocatalysts for CO2RR, although their activities are not ideal and the reaction mechanism is still unclear. Herein, an efficient catalyst is developed for CO2-to-CO conversion realized on diverse N-Cb materials with hierarchical pore structures. It is demonstrated that the CO2-to-CO conversion preferentially takes place on positively charged carbon atoms next to pyridinic-N using two representatives treated pollens with the largest difference in pyridinic-N density and N content as model photocatalysts. Systematic experimental results indicate that surface local electric field originating from charge separation can be boosted by hierarchical pore structures, doped N, as well as pyridinic-N. Mechanistic studies reveal that positively charged carbon atoms next to pyridinic-N serve as active sites for CO2RR, reduce the energy barrier on the formation of CO*, and facilitate the CO2RR performance. All these benefits cooperatively contribute to treated chrysanthemum pollen catalyst exhibiting excellent CO formation rate of 203.2 µmol h?1 g?1 with 97.2% selectivity in pure water vapor. These results provide a new perspective into CO2RR on N-Cb, which shall guide the design of nature-based photocatalysts for high-performance solar-fuel generation. |
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Keywords: | carbon-based materials metal-free catalysts nitrogen doping photocatalytic CO
2 reduction |
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