Influence of Sr leaching on the catalytic activity of reconstructed SrTiO₃ photoelectrodes

Perovskite photoelectrodes are being extensively studied in the search for photocatalytic materials for hydrogen production through water splitting. The solar-to-hydrogen efficiency for these materials is critically dependent on the electrochemical state of their surface. Here, we develop an embedded quantum-mechanical approach using the self-consistent continuum solvation (SCCS) model to predict the relation between electrochemical stability, band alignment, and photocatalytic activity taking into account the long-range polarization of the semiconductor electrode under electrical bias. Using this comprehensive model, we calculate the charge-voltage response of various reconstructions of a solvated SrTiO₃ surface, revealing that interfacial charge trapping exerts primary control on the electrical response, electronic structure, and surface stability of the photoelectrode. Our results provide a detailed molecular-level interpretation of the enhanced photocatalytic activity of SrTiO₃ upon the voltage-induced restructuring of the semiconductor–solution interface.