PVP-assisted synthesis and visible light catalytic property of Ag/AgBr/TiO2 ternary nanostructures

Ag/AgBr/TiO2 nanocomposite was achieved via a sol-gel process in the presence of polyvinylpyrrolidone (PVP) at room temperature. PVP not only regulated the sol-gel process, ensuring the generation of small sized particles with good dispersion, but also reduced Ag+ to Ag particles and formed Ag/AgBr/TiO2 noble metal-sensitizer-semiconductor ternary assemblies. The X-ray diffraction, X-ray photoelectron spectroscopy spectra and energy dispersive spectroscopy results showed Ag (0) existed in the initial products, which was generated by the reduction of AgNO3 by PVP without UV irradiation. Degradation of rhodamine B was selected to evaluate the photocatalytic activity of the Ag/AgBr/TiO2 nanocomposites and a complete degradation of the RhB in solutions (0.0062 g/L, 1.29 x 10(-5) mol/L) could be achieved in 40 min. After six cycles, the photocatalytic activity of the products kept nearly unchanged, illustrating their high stability under visible light. (C) 2013 Elsevier B.V. All rights reserved.