Unusual Photoactive Water Oxidation Activity of Pt/PtO x Cocatalyst Decorated Crystalline α‐Fe 2 O 3 Nanostructures: Exposed Facets Dependent Reactivity

A key challenge remains the preparation of an active and robust water oxidation photocatalyst with abundant earth materials. As a useful to improve photocatalytic efficiency, the development of α‐Fe 2 O 3 nanocrystals with different exposed facets and interfaces has attracted enormous attention. But literature survey shows that α‐Fe 2 O 3 nanomaterials were mainly used in photoelectrochemical cell for water splitting as anode materials. In this work, highly efficient Pt/PtO x cocatalyst decorated α‐Fe 2 O 3 shaped‐photocatalysts were derived as photocatalyst for white light‐induced O 2 generation from water without any electric potential. The maximum apparent quantum efficiency of photooxidation reaction was reached 55.33 % by Pt/PtO x decorated bitruncated‐dodecahedron shaped α‐Fe 2 O 3 and around 30.5, 2.3, 1.28 times better than the Pt/PtO x decorated nanocuboid, nanorod and bitruncated‐octahedron shape respectively. The Pt/PtO x decorated bitruncated‐dodecahedron shaped α‐Fe 2 O 3 display an unusual photooxidation activity with a high TOF (1.96×10 −2  s −1 ) due to presence of destabilized and unsaturated Fe centre containing high energy {104} and {100} facets. The present findings clearly demonstrate that the selective O 2 evolution from water can possible without any sacrificial agent.