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

Abstract

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.

Recent Progress on Nanostructured Layered Double Hydroxides for Visible‐Light‐Induced Photoreduction of CO2

“…[29c] The novel 2D/2D interface heterojunction showed superior performance in producing CO by improving transfer, and suppressing recombination of photoinduced carriers. [32] Zou and co-workers also found similar results in CoZnAl-LDH/RGO/g-C 3 N 4 (LDH/RGO/CN) Z-scheme systems. Moreover, they found RGO was an electron mediator promoting charge separation in CO 2 PR (Figure 5e-f).…”

Enhancing photovoltages at p-type semiconductors through a redox-active metal-organic framework surface coating

“…In this study, the electrochemical potential required to achieve equivalent rates of H 2 evolution was 550 mV less under illumination than that of the MOS at glassy carbon electrodes. More recently, a Cu-based MOF at a Cu 2 O photoelectrode operated in acetonitrile was used to enhance the CO 2 reduction activity of the Cu 2 O surface 27 .…”

Defect Engineering of Photocatalysts for Solar Energy Conversion

“…For instance, the charge dynamics in real time of defective ZnIn 2 S 4 layers was conducted by ultrafast TA spectroscopy (Figure a,b), indicating that massive photoexcited electrons were produced owe to high zinc vacancies and the charge separation efficiency could be enhanced by the long‐lived electrons, thus improving the performance of PC CO 2 conversion . Xiong et al employed ultrafast TA spectroscopy to determine the charge dynamics of Cu 2 O and Cu 3 (BTC) 2 /Cu 2 O, indicating a preferential way of the electrons, thus boosting PEC CO 2 conversion (Figure c) . According to the analysis of TA spectroscopy (Figure d), the distribution of charge transfer was confirmed in CdS‐Au‐TiO 2 .…”

“…Copyright 2017, American Chemical Society. c) Ultrafast TA spectroscopy of Cu 2 O and Cu 3 (BTC) 2 /Cu 2 O. Reproduced with permission . Copyright 2019, American Chemical Society.…”