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

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%.