Sono- and Photochemical Routes for the Formation of Highly Dispersed Gold Nanoclusters in Mesoporous Titania Films


  • The authors are indebted to Mr. T. K. Cheung and Prof. Q. Li for the TEM measurements and helpful discussions. The work was supported by the Innovation and Technology Fund (ITS/118/01) and Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. 402904).


A sono- and photochemical approach has been developed to incorporate highly dispersed gold nanoclusters into mesoporous TiO2 films. The first step involves the sonication of a TiO2 film immersed in a gold chloride solution. This effectively removes the air trapped in the porous film matrix and drives the gold chloride into the pore channels, leading to a homogeneous adsorption of ionic Au in the TiO2 mesoporous matrix. The second step takes advantage of the photocatalytic property of TiO2 to reduce the adsorbed Au ions to Au0. As the gold nanoclusters thus produced are stabilized by the TiO2 mesonetwork, no organic capping molecules are required. Highly dispersed Au/TiO2 nanoheterojunction arrays can be obtained using this interesting approach.