Ag/ɑ-Fe2O3 nanowire arrays enable effectively photoelectrocatalytic reduction of carbon dioxide to methanol

The photoelectrochemical (PEC) reduction of CO2 into useful fuels using environmentally friendly and visible-light-driven catalysts is a promising approach for mitigating CO2 emissions. Herein, ɑ-Fe2O3 nanowire arrays coupled with Ag nanoparticles (Ag/ɑ-Fe2O3) are realized by electrodeposition following post photoreduction process. As a result, the Ag/ɑ-Fe2O3 photoelectrode shows remarkably improved catalytic properties towards the PEC reduction of CO2, particularly for the methanol production, with a rate of 11.72 mmol cm−2 h−1 and a Faradaic efficiency of 51%, which are all much higher than those achieved on bare ɑ-Fe2O3. Meantime, the catalytic activity of the Ag/ɑ-Fe2O3 photoelectrode proceeds without deactivation even after 50 h. The improved photoelectrocatalytic performances can be attributed to the plasmonic Ag nanoparticles with enhanced charge generation and separation, as well as transport over the Ag/ɑ-Fe2O3 nanowire arrays. This work will shed light on designing efficient and robust catalysts for PEC reduction of CO2.