Enhancing the photocatalytic activity of Ruddlesden-Popper Sr2TiO4for hydrogen evolution through synergistic silver doping and moderate reducing pretreatment

The photocatalytic hydrogen (H2) generation relies heavily on the properties of photocatalysts, including their light absorption, charge transport, and oxygen vacancy of photocatalysts. In this work, we have successfully synthesized Ruddlesden-Popper (RP) perovskite Sr2TiO4as photocatalysts for H2evolution reaction (HER). Importantly, we adopted a facile and effective strategy of Ag doping and reducing pretreatment to tailor the properties of Sr2TiO4photocatalysts. The synergistic effect of Ag doping and moderate reducing pretreatment confers Sr2TiO4photocatalyst with improved morphological characteristics, increased specific surface area, optimized light absorption capability and band gap, suppressed charge carrier recombination as well as increased amount of surface oxygen vacancies. Benefiting from these merits, r-Ag0.05Sr1.95TiO4with suitable amount of Ag doping and moderate reducing pretreatment displays an excellent photocatalytic performance for H2generation, which presents average hydrogen production rates of 1695 μmol h-1g-1and 541 μmol h-1g-1under full range light irradiation (λ ≥ 250 nm) and visible light irradiation (λ ≥ 400 nm), respectively.