Light‐Induced Water Splitting with Hematite: Improved Nanostructure and Iridium Oxide Catalysis

Revved-up rust! Light-induced water splitting over iron oxide (hematite) has been achieved by using a particle-assisted deposition technique and IrO2-based surface catalysis. Photocurrents in excess of 3 mA cm−2 were obtained at +1.23 V versus the reversible hydrogen electrode under AM 1.5 G 100 mW cm−2 simulated sunlight. These photocurrents are unmatched by any other oxide-based photoanode. FTO=fluorine-doped tin oxide.