Water Splitting: Why Tin‐Doping Enhances the Efficiency of Hematite Photoanodes for Water Splitting—The Full Picture (Adv. Funct. Mater. 52/2018)

Photoelectrical water oxidation by photoanodes comprised of ultrathin hematite films is investigated by Christina Scheu, Rossitza Pentcheva, and co-workers in article number 1804472. It is determined that on-surface tin doping prevents hole-trapping and lowers the overpotential. Sub-surface tin doping, provided the bulk remains undoped, introduces a band gradient, thereby enhancing charge separation efficiency. The results will be useful in developing high-performance water splitting systems.