Photothermal Synergistic Hydrogen Production via a Fly‐Ash‐made Interfacial Vaporific System

Employing UV-vis spectrum for hydrogen generation and vis-IR spectrum to elevate reaction temperatures and induce phase transitions effectively enhances yield and purifies water, demonstrating a judicious strategy for solar energy utilization. This study presents an interfacial photothermal water splitting system that utilizes all-inorganic, economical industrial by-products known as fly ash cenospheres (FAC) for solar-driven hydrogen generation. In this system, the yield reaches 254.8 µmol h^-1 cm^-1, representing an 89% augmentation compared to that of the three-phase system. In situ experiments, combined with theoretical calculation, reveal the system's robust light absorption capacity, facilitating rapid gas separation, thus improves the solar-to-hydrogen (STH) efficiency. Furthermore, the system demonstrates strong performance in turbid water and scalability for expansive applications, achieving a hydrogen yield exceeding 50 L h^-1 m^-2 from various water sources. Facilitating large-scale hydrogen production and water purification, it thereby establishing its potential as a viable solution for sustainable energy generation.