S-scheme heterojunction of crystalline carbon nitride nanosheets and ultrafine WO_(3)nanoparticles for photocatalytic CO_(2)reduction  

作　　者：Gongjie Chen Ziruo Zhou Bifang Li Xiahui Lin Can Yang Yuanxing Fang Wei Lin Yidong Hou Guigang Zhang Sibo Wang 

机构地区：[1]State Key Laboratory of Photocatalysis on Energy and Environment,College of Chemistry,Fuzhou University,Fujian 350116,China

出　　处：《Journal of Environmental Sciences》2024年第6期103-112,共10页环境科学学报（英文版）

基　　金：supported by the National Key R&D Program of China(Nos.2021YFA1502100 and 2022YFE0114800);the National Natural Science Foundation of China(Nos.22311540011 and 21973014)。

摘　　要：Highly crystalline carbon nitride polymers have shown great opportunities in overall water photosplitting;however,their mission in light-driven CO_(2)conversion remains to be explored.In this work,crystalline carbon nitride(CCN)nanosheets of poly triazine imide(PTI)embedded with melon domains are fabricated by KCl/LiCl-mediated polycondensation of dicyandiamide,the surface of which is subsequently deposited with ultrafine WO_(3)nanoparticles to construct the CCN/WO_(3)heterostructure with a S-scheme interface.Systematic characterizations have been conducted to reveal the compositions and structures of the S-scheme CCN/WO_(3)hybrid,featuring strengthened optical capture,enhanced CO_(2)adsorption and activation,attractive textural properties,as well as spatial separation and directed movement of light-triggered charge carriers.Under mild conditions,the CCN/WO_(3)catalyst with optimized composition displays a high photocatalytic activity for reducing CO_(2)to CO in a rate of 23.0μmol/hr(i.e.,2300μmol/(hr·g)),which is about 7-fold that of pristine CCN,along with a high CO selectivity of 90.6%against H2formation.Moreover,it also manifests high stability and fine reusability for the CO_(2)conversion reaction.The CO_(2)adsorption and conversion processes on the catalyst are monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),identifying the crucial intermediates of CO_(2)^(*)-,COOH^(*)and CO^(*),which integrated with the results of performance evaluation proposes the possible CO_(2)reduction mechanism.

关 键 词：Crystalline carbon nitride Photocatalysis CO_(2)reduction S-scheme WO_(3) 

分 类 号：X701[环境科学与工程—环境工程]