Crystal Water in Minerals Modulates Oxygen Activation for Hydrogen Peroxide Photosynthesis.

Sunlight-responsive minerals contribute significantly to biogeochemical cycles by activating oxygen (O) to generate reactive oxygen species (ROS). However, the role of crystal water, incorporated into minerals through hydration during rock cycles, in O activation remains largely unexplored. Here, we construct tungstite models containing oxygen vacancies to elucidate the modulation of mineral-based ROS dynamics by the synergy between oxygen vacancy and crystal water. Crystal water promotes the protonation process of superoxide anion radicals to produce hydrogen peroxide (HO) and alleviates its decomposition. This mineral-based HO photosynthesis system efficiently eliminates organic pollutants in a sequential light-dark reaction. Furthermore, this synergy effect can extend to other metal oxide minerals such as TiO, SnO, CuO, ZnO, and BiO. Our results illuminate an overlooked pathway for modulating the protonation process by immobilized water in hydrous minerals, playing a crucial role in ROS storage and migration and pollutant dynamics in a natural environment throughout the day/night cycle.