Performance of amorphous TiO2@Ag/AgBr composite photocatalyst prepared by spray pyrolysis

Abstract

Amorphous titanium dioxide was prepared by spray pyrolysis using TiCl4 as the precursor, and the TiO2@Ag/AgBr composite photocatalyst was synthesized by the oil-in-water self-assembly method with AgNO3 as the silver source. The microstructure and valence state of the samples were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. The surface morphology of the samples was observed by scanning electron microscope and transmission electron microscope. The light absorption range and electronic recombination behavior of the samples were characterized by UV-Vis diffuse reflection spectrometer, fluorescence spectrophotometer, and electrochemical impedance spectroscopy. The photocatalytic performance was studied by degrading methyl orange under the natural light conditions, and the effect of Ag/AgBr loading capacity on the photocatalytic performance was discussed. The results show that, the prepared titanium dioxide is an amorphous nano-scale spherical particle with the diameter of less than 500 nm. Ag/AgBr is uniformly loaded on the TiO2 surface. The prepared TiO2@Ag/AgBr composite photocatalysts all show the good photocatalytic activity. The degradation efficiency of methyl orange by the TiO2@Ag/AgBr composite photocatalyst with the best loading capacity can reach 91%.

Keywords

• spray pyrolysis
• amorphous titanium dioxide
• photocatalysis
• silver bromide
• composites