Spherical Titania Composite Preparation And Its Photocatalytic Activity

Spherical titanium dioxide has low-density, large specific surface area, but also as three-dimensional structure of materials, which attracted widespread attention in recent years. However, titanium dioxide is a wide band gap semiconductor, one drawback of titanium is that it can't be excited by visible light. In order to improve its photocatalytic activity, in this paper we prepared sliver nanopartical loading spherical titanium dioxide and join phosphate silver semiconductor with titanium dioxide to form a visible light activity of heterogeneous photocatalysis materials In this paper, hydrothermal methods to prepare spherical titanium dioxide powder and film formed by the spherical titanium dioxide, we optimized its preparation program parameters. In addition, the morphology, structure, valence state was test by XRD, SEM, XPS, TEM, UV-vis other means.Ag/TiO₂ prepared by dipping-photoreduction and hydrothermal two methods, were recorded as Ag/TiO₂ (Ⅰ) and Ag/TiO₂ (Ⅱ) respectively. As the result of surface plasmons resonance, Ag/TiO₂ (Ⅰ) and Ag/TiO₂ (Ⅱ) have absorption in the visible light region, and both of them can degrade methyl orange under the visible light. As Ag/TiO₂ (Ⅱ) absorption in the visible region wider more than Ag/TiO₂ (Ⅰ), more light absorption intensity, which lead to Ag/TiO₂ (Ⅱ) photocatalytic activity is much higher than Ag/TiO₂ (Ⅰ).One-step hydrothermal method can be more effectively to load the Ag on the spherical titanium dioxide. XRD, TEM, XPS results show that one-step hydrothermal preparation Ag/TiO₂ (Ⅱ) in the elemental state of Ag is present. Adjustment the Ag/Ti mole ratio in the hydrothermal for preparing Ag/TiO₂ (Ⅱ), the catalytic activity is different, when the Ag/Ti = 0.05, Ag/TiO₂ (Ⅱ) degradation methyl orange photocatalytic performance is the best.This article also prepared film formed by the titanium microspheres throw hydrothermal method. We studied the effect of HF acid concentration, reaction temperature, reaction time and the sintering temperature on film morphology and photocatalytic properties. Through multiple impregnation, composite TiO₂ with Ag₃PO₄ compound semiconductor films. Ag₃PO₄ composite of optical absorption edge of the film to 510nm, the visible light photocatalytic can be degradation of methyl orange, that there is visible activity of the film. Investigated the times of film impregnated with photocatalytic activity, the results show that the number of immersion in 5 times, the films has the best photocatalytic activity .