Improved overall water splitting for hydrogen production on aluminium-doped SrTiO₃ photocatalyst via tuned surface band bending

Future carbon neutrality and the energy crisis are calling for advanced methods to produce sustainable fuels such as hydrogen production by photocatalytic water splitting. For that, the aluminum-doped SrTiO₃ photocatalyst is promising, yet controlling aluminum is challenging, and the underlying mechanism is poorly known. Here, we synthesized SrTiO₃ nanoparticles with controllable aluminum doping by a mild hydrothermal method, and we studied the photocatalytic overall water splitting by experimental and theoretical analysis. Results show a production of H₂ of about 4.1 mmol h⁻¹ g⁻¹, and O₂ of about 1.9 mmol h⁻¹ g⁻¹. This excellent photocatalytic performance is explained by improved charge separation and accelerated redox reaction, resulting from tuned surface band bending of SrTiO₃ realized by regulation of the Fermi level. Overall, we have revealed the mechanism by which aluminum doping improves the photocatalytic performance, from the perspective of surface band bending.