Bifunctional Nanocatalyst of Bimetallic Nanoparticle/TiO₂ with Enhanced Performance in Electrochemical and Photoelectrochemical Applications

A novel metal/semiconductor hybrid nanostructure with enhanced catalytic functions has been prepared by a simple self-assembly approach. This new bifunctional nanocatalyst consists of evenly dispersed Au/Pt hybrid nanoparticles (Au/Pt NPs) assembled on NH(2) group functionalized anatase TiO(2) colloid spheres with nanoporous surface (f-TiO(2)). The resulting bimetallic nanoparticles/TiO(2) (noted as f-TiO(2)-Au/Pt NPs) hybrid nanostructure is characterized by various methods and expected as a promising catalyst in electrochemical and photoelectrochemical applications because of its satisfactory or even enhanced catalytic properties from both TiO(2) and Au/Pt NPs. Compared with the f-TiO(2), the electrochemical results indicate that the as-prepared f-TiO(2)-Au/Pt NPs exhibited more prominent electrocatalytic reduction toward hydrogen peroxide at low potential, which was then used as a sensitive sensor with a detection limit of 75 nM. Most importantly, the present hybrid material has the better photocatalytic property, as demonstrated by the photoelectrochemical catalysis of glucose.