PVP-assisted synthesis and visible light catalytic property of Ag/AgBr/TiO_2 ternary nanostructures

摘要

Ag/AgBr/TiO_2 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/TiO_2 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 AgNO_3 by PVP without UV irradiation. Degradation of rhoda-mine B was selected to evaluate the photocatalytic activity of the Ag/AgBr/TiO_2 nanocomposites and a complete degradation of the RhB in solutions (0.0062 g/L, 1.29 × 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.