Recent advances in synthesis strategies and solar-to-hydrogen evolution of 1T phase MS2 (M = W, Mo) co-catalysts

Photocatalytic water splitting is a promising strategy to produce hydrogen as a sustainable and clean energy carrier, based on abundant solar energy and semiconductor photocatalysts, and it has received extensive research and discussion over the past several decades. It is challenging, however, to achieve an efficient solar-to-hydrogen evolution process with a single particulate photocatalyst due to the weak solar spectrum harvest and the rapid recombination of photogenerated electron-hole pairs during the photocatalysis reaction. Combining semiconductors to create different co-catalysts presents a viable solution to the above issues. Recently, semiconductor photocatalysts modified by different transition metal sulfide-based co-catalysts with designed functions, especially in light absorption enhancement and charge-carrier-separation efficiency promotion, have attracted much attention. As continued breakthroughs have been made in the preparation, modification, and solar-to-hydrogen evolution application of the 1T phase MS2 (M = W, Mo) co-catalyst-based photocatalysis system in recent years, we believe that a comprehensive review of this kind of co-catalyst would further promote its research and development to address the energy and environmental challenges that we are currently facing. Herein, recent studies and progress are summarized on the fabrication of 1T phase MS2 (M = W, Mo)-based co-catalyst materials, as well as their roles and functional mechanisms for photocatalytic H2 evolution. Finally, concluding perspectives on the opportunities in and challenges for the further exploration of the 1T-MS2 (M = W, Mo)-based solar-to-hydrogen evolution system are presented.