Photogenerated Carrier-Assisted Electrocatalysts for Efficient Water Splitting

Electrocatalysts are the core component of electrocatalytic water splitting for improving its overall energy conversion efficiency and reducing the energy input. At present, the design of efficient electrocatalysts mainly focuses on optimizing their electronic structure and local reaction microenvironment to improve the adsorption of reaction intermediates. Although many effective strategies (such as heteroatom doping, vacancy, heterojunction construction, strain engineering, and phase transformation) have been developed, the improvement in catalytic activity has been very limited. Hence, the development of innovative strategies to enhance the optimization of photoelectroactivity is desirable. Inspired by the strategy of applying a potential field to reduce carrier radiation recombination in traditional photoelectrocatalysis, photogenerated carrier-assisted electrocatalysis, based on the synergy effect of light and electric energy, provides a new strategy to enhance the intrinsic activity of water splitting. The essence of the photo-assisted strategy can be attributed to the injection of hot carriers and photogenerated electron–hole pairs or the accelerated reaction kinetics caused by local temperature rises. The photogenerated carrier-assisted strategy has received wide attention due to its simplicity and efficiency. In this review, we focus on the recent advances in photogenerated carrier-assisted strategies (PCAS) for enhancing the performance of HER, OER, and overall water splitting. The possible mechanisms are addressed and the basic composition and latest progress in photo-assisted electrocatalysts using PCAS are summarized. Finally, the challenges and development prospects of PCAS will be detailed.