Recent advances in suppressing the photocorrosion of cuprous oxide for photocatalytic and photoelectrochemical energy conversion

The emergence of cuprous oxide (Cu2O) as a visible light active semiconductor for photocatalytic and photoelectrochemical applications has elevated significantly over the past decade. With photocorrosion identified as a severe issue for Cu2O, its photoactivity has been greatly restricted. Given that Cu2O redox potentials are located in between its band gap, the possible occurrence of self-photoreduction or self-oxidation upon illumination is inevitable. Various efforts have been directed to implement effective strategies in enhancing the photostability of Cu2O. In particular, most of the studies focused on improving the charge transfer from Cu2O to reactants or co-catalyst to avoid accumulation of charge within the particles. This review presents recent research progresses for the development of strategies to suppress Cu2O photocorrosion in regards to its intrinsic properties and charge kinetics. It is shown that effective transport of electrons or holes out of Cu2O photocatalyst by engineering its crystal structure, tuning its reaction environment or depositing secondary elements could effectively inhibit Cu2O from experiencing self-photodecomposition. Understanding of the charge dynamics with respect to its photocorrosion is pivotal to optimize the design of Cu2O photocatalyst for enhanced performance in the future.