Core–Shell In/Cu2O Nanowires Schottky Junction for Enhanced Photoelectrochemical CO2Reduction under Visible Light

Abstract

Photoelectrochemical (PEC) CO2 reduction into chemical fuels is a promising strategy to alleviate the energy and environmental crisis. However, it remains a challenge to design efficient photocathodes for PEC CO2 reduction. Here, we constructed Cu2O-indium (In) core–shell nanowires Schottky junction assisted by physical vapor deposition to boost PEC CO2 reduction. The research of charge transport kinetics shows that the construction of Schottky junction effectively promotes the transfer and separation of photogenerated electrons. In addition, the introduction of In improves the catalytic activity of the Cu2O, and the CO yield reaches 75.94 μmol cm–2 h–1 at −0.7 V vs RHE. The In/Cu2O photocathode exhibits consistent Faradaic efficiency for CO (82%) over 12 h. In situ Fourier transformed infrared spectroscopy spectra results indicate that the introduction of In promotes the absorption and accumulation of COOH* intermediate, thereby promoting the release of CO. The study proposes a feasible strategy for designing and fabricating PEC CO2 reduction photocathodes with high catalytic activity to treat atmospheric CO2.