Recent advances and challenges of photoelectrochemical cells for hydrogen production

Photoelectrocatalytic water splitting and organic reforming have recently received significant attention among researchers due to the potential opportunity to convert sunlight into hydrogen energy using efficient and low-cost photoelectrode materials under practical operating conditions. This paper discusses an overview of various aspects related to the implementation of photoelectrochemical (PEC) cells for hydrogen generation. Information on (i) reaction energies of photosplitting and photoreforming, (ii) state-of-the-art semiconductor-based materials for PEC hydrogen evolution reaction (HER) active both under UV and visible-light irradiation, (iii) PEC photo-efficiency indicators, and (iv) criteria for the standardization of photoelectrochemical reactor performances are summarized. This short review provides a fundamental background to highlight the most effective approaches developed to date in PEC research and promote future competitive large-scale systems for hydrogen generation for practical applications.