首页|Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO2 Molecules Enhances CO2 Photoreduction

Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO2 Molecules Enhances CO2 Photoreduction

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Photocatalytic reduction of CO2 into fuels provides a prospective tactic for regulating the global carbon balance utilizing renewable solar energy.However,CO2 molecules are difficult to activate and reduce due to the thermodynamic stability and chemical inertness.In this work,we develop a novel strategy to promote the adsorption and activation of CO2 molecules via the rapid energy exchange between the photoinduced Br vacancies and CO2 molecules.Combining insitu continuous wave-electron paramagnetic resonance(cw-EPR)and pulsed EPR technologies,we observe that the spin-spin relaxation time(T2)of BiOBr is decreased by 198 ns during the CO2 photoreduction reaction,which is further confirmed by the broadened EPR linewidth.This result reveals that there is an energy exchange interaction between in situ formed Br vacancies and CO2 molecules,which promotes the formation of high-energy CO2 molecules to facilitate the subsequent reduction reaction.In addition,theoretical calculations indicate that the bended CO2 adsorption configuration on the surface of BiOBr with Br vacancies caused the decrease of the lowest unoccupied molecular orbital of the CO2 molecule,which makes it easier for CO2 molecules to acquire electrons and get activated.In situ diffuse reflectance infrared Fourier transform spectroscopy further shows that the activated CO2 molecules are favorably converted to key intermediates of COOH*,resulting in a CO generation rate of 9.1 pmol g-1 h-1 and a selectivity of 100%.This study elucidates the underlying mechanism of CO2 activation at active sites and deepens the understanding of CO2 photoreduction reaction.

Qin Ren、Ye He、Hong Wang、Yanjuan Sun、Fan Dong

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Research Center for Environmental and Energy Catalysis,Institute of Fundamental and Frontier Sciences,University of Electronic Science and Technology of China,Chengdu 611731,China

School of Resources and Environment,University of Electronic Science and Technology of China,Chengdu 611731,China

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaSichuan Natural Science Foundation for Distinguished Scholars

222256062217201922261142663221760292021JDJQ0006

2024

研究(英文)

研究(英文)

CSTPCD
ISSN:
年,卷(期):2024.2024(2)
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