To Stabilize Oxygen on In/In2O3 Heterostructure via Joule Heating for Efficient Electrocatalytic CO2 Reduction

Abstract The regulation of interfacial chemistry for the electrocatalytic reduction of CO 2 into valuable fuels is highly promising but still challenging. Herein, an advanced strategy is developed to modulate the interfacial oxygen species on the hierarchical indium oxide nanosheets. The rapid Joule heating to an elevated temperature is demonstrated to stabilize oxygen species against the electrochemical reduction. Thus, the formation of heterogeneous interface with desirable oxygen species enables to improve electrocatalytic performance. Typically, the obtained electrocatalysts display the high Faradaic efficiency of 94% for carbon dioxide reduction (CO 2 RR) into formate and ≈100% for C1 products in the wide potential range from −0.5 to −1.0 V, outperforming most of the state‐of‐art indium‐based catalysts. The in situ experimental characterization and theoretical calculation reveal that the heterointerface with stable InO species would regulate the d‐band center to optimize the electronic structure and thus accelerate the protonation process from bicarbonate species adsorbed, leading to the enhanced performance. With the fundamental understanding, the solar‐driven CO 2 ‐H 2 O cell is constructed to achieve a good energy conversion efficiency of 13.4%. This study offers a feasible strategy to modulate the interfacial structures and properties toward the rational design of advanced electrocatalysts.