Dealloying induced plasmonic Au nanoparticle modified mesoporous TiO2 for enhanced visible light photocatalysis

Abstract

Plasmonic noble metallic nanoparticles have emerged as a promising material in sensitizing wide-bandgap semiconductors for visible-light photocatalysis. However, the preparation of plasmonic metallic nanoparticles and the aggregation of metallic nanoparticles are the common troubles. Here, Au nanoparticles with uniform distribution on the matrix have been achieved by a dealloying method. Two kinds of Au/TiO₂ nanocomposites were prepared by calcination and hydrothermal synthesis of the dealloying induced Au/H-titanate precursor. The Au/TiO₂ nanocomposites present a mesoporous structure with a large specific surface area. By comparison, the Au/TiO₂ nanocomposites obtained by calcination exhibit greatly enhanced photocatalytic activity for the degradation of methyl orange under irradiation of visible light. The monodisperse Au nanoparticles, large specific surface area and good interaction between Au and TiO₂ are favorable for the enhanced visible light photocatalytic activity of Au/TiO₂ nanocomposites fabricated by calcination.