Progress in manipulating spin polarization for solar hydrogen production

Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel. In the past few years, a series of photocatalysts/photoelectrocatalysts have been developed and optimized to achieve efficient solar hydrogen production. Among various optimization strategies, the regulation of spin polarization can tailor the intrinsic optoelectronic properties for retarding charge recombination and enhancing surface reactions, thus improving the solar-to-hydrogen (STH) efficiency. This review presents recent advances in the regulation of spin polarization to enhance spin polarized-dependent solar hydrogen evolution activity. Specifically, spin polarization manipulation strategies of several typical photocatalysts/photoelectrocatalysts (e.g., metallic oxides, metallic sulfides, non-metallic semiconductors, ferroelectric materials, and chiral molecules) are described. In the end, the critical challenges and perspectives of spin polarization regulation towards future solar energy conversion are briefly provided.