Dependence of Ag Deposition Methods on the Photocatalytic Activity and Surface State of TiO2 with Twistlike Helix Structure

The 1% silver clusters containing twistlike helix titania nanoparticles have been synthesized and tested in photocatalytic applications. The special twistlike helix structures were obtained by controlling the hydrolysis of titanium tetrachloride, while variety of routes were investigated to deposit the silver nanoparticles. where impregnation, chemical deposition, and photodeposition methods are adopted to fabricate the Ag/TiO2 samples. The influence of the photocatalytic activity of the mesoporous helix materials and the preparation methods oil the final structure of the samples was investigated, including the Surface area, pore size, silver crystallite size, silver distribution, and silver surface content. The dispersion and particle size of Ag Clusters or nanoparticles on Ag/TiO2 nanocatalysts were investigated by TEM analysis. The surface Ag nanoparticles contents were determined by XPS results. Diffuse reflectance and photoluminescence analysis were used to investigate the visible light adsorption ability and the active sites amount including photoinduced electrons and holes. The experimental results show that the chemical deposition method is all efficient method to synthesize Ag/TiO2 catalysts with highly dispersed nanoparticles of metallic Ag. The Ag/TiO2 sample prepared through the chemical deposition method shows the best photocatalytic activity, and its photocatalytic activity is Superior to that of P25 and pure TiO2 sample. The Superior activity of A-MO, photocatalysts call be rationalized in terms of well dispersion and Suitable surface content of Ag nanoparticles that will effectively decrease the recombination rate of photoinduced electrons and holes and then increase the photooxidation efficiency of the catalysts.