Evaluating the role of oxygen vacancies in CO_(2) photothermal catalytic reduction to methanol over 2D Bi_(2)WO_(6)  

2D Bi_(2)WO_(6)表面氧空位在光热催化CO_(2)还原制甲醇反应中的作用

作　　者：Hong-Xia Fan Tao Liu Liang-Fen Zhen Antony Rajendran Jie Feng Wen-Ying Li 范鸿霞;刘涛;甄良芬;Antony Rajendran;冯杰;李文英(State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China;Department of Chemistry,Mepco Schlenk Engineering College(Autonomous),Sivakasi 626005,Tamil Nadu,India)

机构地区：[1]State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China [2]Department of Chemistry,Mepco Schlenk Engineering College(Autonomous),Sivakasi 626005,Tamil Nadu,India

出　　处：《Science China Materials》2025年第2期464-471,共8页中国科学(材料科学)(英文版)

基　　金：supported by the National Key R&D Program of China (2022YFE0208400);the National Natural Science Foundation of China (U22A20211 and 22308248);the Fundamental Research Funds for the Central Universities (2022ZFJH04)。

摘　　要：Oxygen vacancies play a vital role in the adsorption,activation,and subsequent reduction of CO_(2) to methanol.This work presents the preparation of two-dimensional Bi_(2)WO_(6) nanosheets with different oxygen vacancy concentrations(BWO-OV1,BWO-OV_(2),and BWO-OV3)and the evaluation of their catalytic activity in the photothermal catalytic reduction of CO_(2) to methanol.The oxygen vacancy concentration has played a decisive role in controlling the methanol yield.The BWO-OV_(2) catalyst with the highest oxygen vacancy concentration(13.9%)accomplishes the maximum methanol yield(82.45μmol/(g h)).This is because the oxygen vacancies enhance the adsorption and activation of CO_(2) in the form of CO_(2)^(-),broaden the light adsorption range,and promote light-induced charge carrier separation.Also,BWO-OV_(2) exhibits 1.91 and 3.28 times higher catalytic activity in CO_(2) reduction while being used under photothermal catalytic conditions than being employed under photocatalytic and thermal catalytic conditions,respectively.In line with the in-situ Fourier transform infrared spectroscopy and computational analysis,the external heat indiscriminately promotes the adsorption and further conversion of all involved intermediates but the light irradiation selectively enhances the adsorption of CO_(2)^(-),HCOO*,and CH_(3)O*species.The findings of the present work might provide key mechanistic insights into understanding the role of thermal and light irradiation in photothermal catalysis.氧空位在CO_(2)吸附、活化以及还原制甲醇过程中至关重要.本研究制备了3种具有不同氧空位浓度的二维Bi_(2)WO_(6)纳米片用于光热催化CO_(2)还原制甲醇,分别是BWO-OV1,BWO-OV_(2)与BWO-OV3.在90℃和300 nm光照条件下,以甲醇产率为考核指标,结果显示,反应4 h后甲醇产率与氧空位浓度呈正相关,氧空位浓度为13.9%的BWO-OV_(2)甲醇产率达82.45μmol/(g h),分别是单独300 nm光照、90℃条件下的1.91和3.28倍.原位红外表征分析表明,Bi_(2)WO_(6)表面氧空位不仅可以促进CO_(2)以CO_(2)形式发生吸附活化,还可以拓宽光吸收范围及促进光生载流子分离.90℃反应温度可以促进反应涉及全部中间体的吸附,光照作用在于选择性增强CO_(2)^(-)、HCOO*和CH_(3)O*的吸附,更有利于甲醇生成.本研究及获得结果信息为理解光热催化反应中热与光照的作用提供了新见解.

关 键 词：Bi_(2)WO_(6)catalysts oxygen vacancy photothermal catalysis CO_(2)reduction METHANOL 

分 类 号：O643.36[理学—物理化学] TQ223.121[理学—化学]