Efficiently enhancing the photocatalytic activity of faceted TiO2 nanocrystals by selectively loading α-Fe2O3 and Pt co-catalysts

Abstract

The loading of oxidation and/or reduction co-catalysts onto the surface of semiconductor nanomaterials is one of the most efficient methods of improving the performance of semiconductor-based photocatalysts. However, in most of cases, the enhancing effect can be weakened by a random co-catalyst loading method because the different roles of photocatalyst facets in the photocatalytic process are not simultaneously considered. In this paper, a ternary composite photocatalyst, Fe₂O₃–TiO₂–Pt, with α-Fe₂O₃ and Pt nanoparticles selectively deposited onto the {001} and {101} facets of TiO₂, respectively, was successfully constructed using the facet-induced photogenerated electrons and holes of well-faceted anatase TiO₂ nanocrystals as natural redox agents. The overall photocatalytic activity of this well-designed composite photocatalyst in H₂ production has been enhanced greatly by as much as 2.2 times and 30 times compared to the photocatalysts loaded randomly and without a co-catalyst, respectively. The enhanced photocatalytic activity of Fe₂O₃–TiO₂–Pt was attributed to the remarkably enhanced separation of photogenerated charge carriers with the excitation of UV light.