Modulation of oxygen vacancies and hot electrons promotes highly efficient CO2 photoreduction towards C2H6

Abstract

Efficient CO2 photoreduction towards C2+ solar fuels has emerged as one of the most promising strategies for alleviating the current energy and environment problems. However, the C-C coupling barriers and complex multi-electron transfer steps still limit the activity and selectivity of CO2-to-C2 photoreduction. Herein, Au nanoparticles (NPs) modified CeO2 with oxygen vacancies (Au/CeO2-VO) were reported for enhancing the CO2-to-C2H6 photoreduction performance. Au/CeO2-VO achieved the high C2H6 activity of 51.7 μmol·g−1·h−1, accompanied with C2H6 selectivity up to 80% in the absence of sacrificial agent. Experimental results combined with theoretical simulation indicated that VO strengthened CO2 adsorption and activated *CO production, and plasmon-induced hot electrons from Au NPs to CeO2-VO facilitated the *CO-*CO dimerization. The synergistic modulation of VO and hot electrons further decreased the energy barriers of C-C coupling and subsequent hydrogenation, resulting in the superior photoreduction performance. This work opens an avenue of developing plasmonic photocatalysts for multi-carbon products from CO2 photoreduction.