Understanding Boosted Selective CO2-to-CO Photoreduction with Pure Water Vapor over Hierarchical Biomass-Derived Carbon Matrix

作者：Jiang, Zhifeng^*; Zhang, Zhiquan; Liang, Jianli; Zhou, Min; Liu, Daobin; Mao, Danjun; Zhang, Qun; Zhang, Wei^*; Li, Huaming; Song, Li; An, Taicheng; Wong, Po Keung^*; Lee, Chun-Sing^*

来源：Advanced Functional Materials, 2023, 33(29).

DOI：10.1002/adfm.202301785

• carbon-based materials
• metal-free catalysts
• nitrogen doping
• photocatalytic CO2 reduction

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-C-b) 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-C-b 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 mu mol h(-1) g(-1) with 97.2% selectivity in pure water vapor. These results provide a new perspective into CO2RR on N-C-b, which shall guide the design of nature-based photocatalysts for high-performance solar-fuel generation.

• 单位
  广东工业大学; 南京大学; 江苏大学