Metal-Organic Framework Coating Enhances the Performance of CuO in Photoelectrochemical CO Reduction

Photoelectrochemical (PEC) reduction of CO 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. CuO 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 CuO photocathode, which can both prevent photocorrosion and offer active sites for CO 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 CuO are dramatically enhanced for PEC CO reduction. This work provides fresh insights into the design of advanced hybrid photoelectrodes and highlights the important role of interfacial charge dynamics in PEC CO conversion.