Enhanced photocatalytic performance of Ag decorated hierarchical micro/nanostructured TiO2 microspheres

Uniform hierarchical micro/nanostructured TiO2 microspheres (MTS) composed of well-crystallized anatase phase nanoparticles were first fabricated by a fast and facile microwave-assisted hydrothermal method, then Ag nanoparticles were further decorated onto MTS by a simple polyvinylpyrrolidone-assisted reduction method (the product was denoted as Ag-MTS). The characterization data indicated that the Ag-MTS sample had a high specific surface area (121 m(2) g(-1)) and abundant mesopores with Ag nanoparticles homogeneously dispersed among the TiO2 nanoparticles. The photocatalytic performance of Ag-MTS for the removal of organic dye methyl orange was evaluated. It was found that Ag-MTS showed an enhanced photocatalytic activity when compared to MTS and commercially available nanosized TiO2 Degussa P25. The hierarchical micro/nanostructure (high specific surface area and abundant mesopores properties) together with Ag decoration contributed to the enhanced photocatalytic activity. In addition, Ag-MTS showed easy recovery feature in the recovery process and high durability in the recycling test, which was expected to be a practical photocatalyst used for wastewater treatment. (C) 2015 Elsevier B.V. All rights reserved.