Recent advances in application of transition metal phosphides for photocatalytic hydrogen production

Searching a sustainable way to efficiently produce hydrogen (H-2) is critical to realizing the "hydrogen economy", which may resolve the global energy and environmental issues nowadays. The conversion of solar energy to hydrogen energy based on photocatalytic water splitting is an ideal technology for environmental-friendly and economically producing H-2. Exploring high-performance and earth-abundant cocatalysts that can replace noble metal-based cocatalysts is essential to achieving highly efficient and cost-effective photocatalytic H-2 production. In recent years, transition metal phosphides (TMPs) have been regarded as promising candidates to replace noble metal-based cocatalysts for photocatalytic H-2 production. This review presents a panorama of the latest progress in the developments of TMPs for photocatalytic H-2 production. Concretely, this review starts with the functions of TMPs in photocatalytic H-2 production, followed by the synthetic strategies of TMPs and the loading methods of TMPs on semiconductors. Then the application and mechanism of the common TMPs in photocatalytic H-2 production are discussed in detail, including iron phosphides, cobalt phosphides and nickel phosphides. Lastly, we provide a comprehensive conclusion and outlook on the major challenges and opportunities for better developments in the future research. It is reasonable to believe that the TMPs is a rising star in photocatalytic H-2 production.