Beyond SrTiO3: Emerging Perovskite Photocatalysts for Solar Water Splitting

Photocatalysis has emerged as a promising strategy for converting solar energy into chemical fuels, offering a sustainable route for hydrogen production through water splitting. While solar energy has been successfully utilized for electricity generation via photovoltaic technologies, extending its use to direct chemical fuel production, analogous to natural photosynthesis, remains a major challenge. A significant breakthrough was recently reported by Takata et al., who demonstrated that Al-doped SrTiO3 loaded with Rh/Cr2O3 & CoOOH cocatalysts can achieve near-unity quantum efficiency for photocatalytic water splitting under ultraviolet irradiation at wavelengths around 350 nm. Motivated by this progress, this review surveys perovskite-based photocatalysts for water splitting with the aim of identifying materials beyond SrTiO3 having the potential to exhibit similar or improved performance. The fundamentals of photocatalytic water splitting and the properties of SrTiO3 and other perovskite families, including oxide, oxynitride, Aurivillius, Dion–Jacobson, and Ruddlesden–Popper perovskites, are discussed. Notably promising perovskite materials with potential for achieving high efficiencies and improved solar-light utilization are highlighted.