Zhengfeng Zhao

Mesoporous Ag/TiO2 nanocomposites with greatly enhanced photocatalytic performance towards degradation of methyl orange under visible light

Ag/TiO2 photocatalysis has received tremendous attention as a potential solution to the worldwide energy shortage and for counteracting environmental degradation. Here, the combination of dealloying with calcination has been used to fabricate mesoporous Ag/TiO2 nanocomposites with a large specific surface area of 90.18 m2 g−1. In these nanocomposites, the Ag nanoparticles are well dispersed in the mesoporous anatase TiO2 matrix with a 3 dimensional network structure. More importantly, the Ag/TiO2 nanocomposites show greatly enhanced photocatalytic performance for the degradation of methyl orange under visible light as well as UV irradiation, compared to commercial P25. The photocatalytic mechanism has been rationalized on the basis of a Schottky junction, co-existence of metallic Ag, and large specific surface area. The present Ag/TiO2 nanocomposites show great potentials for photocatalysis under solar light.

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

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.