Dependence of photocatalytic activities upon the structures of Au/Pd bimetallic nanoparticles immobilized on TiO2 surface

Bimetallic nanoparticles with a Au-core/Pd-shell structure were prepared and successfully immobilized on a TiO2 surface using sonochemical method. When immobilizing the core/shell structured bimetallic nanoparticles with a Au/Pd molar ratio of 25/75, TiO2 showed the highest activity for the photochemical H2 evolution from ethanol aqueous solution. The activities of other two types of photocatalysts with the same Au/Pd molar ratio, TiO2 immobilizing the mixture of Au and Pd monometallic nanoparticle, and TiO2 immobilizing Au/Pd random alloy nanoparticles wherein Au and Pd atoms homogeneously located, were also evaluated. The dependence of the photocatalytic activities on the nanostructures of the immobilized bimetals was confirmed.