Enhanced Photocatalysis by Au Nanoparticle Loading on TiO2 Single-Crystal (001) and (110) Facets

Although the preparation of TiO2 exposed with high-energy facets is a challenge, these facets have a large application potential in the loading of Au nanoparticles. We successfully prepared TiO2 single crystals exposed with (001) and (110) facets as an ideal support to load the highly dispersed nanosized Au particles to improve the stability of Au on the catalyst surface and expand its photocatalytic applications. The transfer of photoexcited electrons from the higher-surface-energy facet, that is, (001) and (110), to the lower-energy facet of (101) could make the electrons aggregate on the (101) facet and leave holes on the (001) and (110) facets, which would promote the separation of electrons and holes. The highly dispersed Au nanoparticles also could capture the electrons from active facets and further improve the photocatalytic activity of TiO2. Systematic density functional theory calculation was also carried out to investigate the formation of (001) and (110) facets.