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.