In Situ Generation of Anatase-Rutile TiO₂/g-C₃N₄ Composite Catalyst in High-Temperature Molten Salt

Hydrogen evolution from water, catalyzed by solar energy, is a promising yet challenging endeavor. Small-sized catalysts usually exhibit high utilization and high performance in the hydrogen evolution field. However, the high surface energy tends to make them aggregate. In this study, we introduce a novel molten salt synthesis technique to develop a composite catalyst featuring a TiO₂/C₃N₄ heterojunction to stabilize the small-sized TiO₂. High-temperature molten salts create a highly polarized environment that facilitates the formation of a smaller-sized Ti precursor, thereby enhancing the integration of the heterojunction with C₃N₄ structures and significantly improving the photocatalytic hydrogen evolution performance. Additionally, the oxidation of sacrificial reagents was examined using a quasi-in-situ NMR technique, with a comprehensive discussion of the reaction products and mechanisms. This research offers valuable insights for employing the molten salt approach in the development of photocatalysts and other functional materials.