Metal-Organic Framework Coating Enhances the Performance of Cu2O in Photoelectrochemical CO2 Reduction.

Photoelectrochemical (PEC) reduction of CO2 into chemical fuels and chemical building blocks is a promising strategy for addressing the energy and environmental challenges, which relies on the development of p-type photocathodes. Cu2O is such a p-type semiconductor for photocathodes but commonly suffers from detrimental photocorrosion and chemical changes. In this communication, we develop a facile procedure for coating a metal-organic framework (MOF) on the surface of a Cu2O photocathode, which can both prevent photocorrosion and offer active sites for CO2 reduction. As evidenced by ultrafast spectroscopy, the formed interface can effectively promote charge separation and transfer. As a result, both the activity and durability of Cu2O are dramatically enhanced for PEC CO2 reduction. This work provides fresh insights into the design of advanced hybrid photoelectrodes and highlights the important role of interfacial charge dynamics in PEC CO2 conversion.