Improving the visible light photocatalytic activity of mesoporous TiO 2 via the synergetic effects of B doping and Ag loading

Abstract

B-doped together with Ag-loaded mesoporous TiO 2 (Ag/B–TiO 2) was prepared by a two-step hydrothermal method in the presence of boric acid, triblock copolymer surfactant, and silver nitrate, followed by heat treatment. The obtained samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption. It was revealed that all samples consist of highly crystalline anatase with mesoporous structure. For Ag/B–TiO 2, B was doped into TiO 2 matrix in the form of both interstitial B and substitutional B while Ag was deposited on the surface of B–TiO 2 in the form of metallic silver. Compared with the single B-doped or Ag-loaded TiO 2 one, mesoporous Ag/B–TiO 2 exhibits much higher visible light photocatalytic activity for the degradation of Rhodamine 6G, which can be ascribed to the synergistic effects of B doping and Ag loading by narrowing the band gap of the photocatalyst and preventing the fast recombination of the photogenerated charge carriers, respectively.