本文阐述了光催化氧化反应的反应机理及其在工业废水和气相污染物处理中的应用,简要地分析了光催化氧化反应速率的影响因素和今后光催化氧化技术的发展方向。

>400nm) were studied. The catalysts weresynthesized by impregnating doped titania sol into the interlayer of montmorillonite (MMT) and characterizedby the UV-vis diffuse reflectance spectra, transmission electron microscopy, and the FT-IR absorption spectra.The ordered structure of MMT was destroyed to some extent and the size of TiO

The preparation methods of the niobate,including solid state reaction, hydrothermal synthesis, sol-gel and co-precipitation are introduced, the research progress of application of niobate compounds to water splitting, photodegradation of organic compounds, organic syntheses, decomposition of the industrial stack gas, purifying automotive exhaust NOx are discussed.

A novel photocatalyst, N and S co-doped TiO2–montmorillonite (NST–MMT), was synthesized by impregnating doped titania sol into the interlayers of MMT and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET). The XRD patterns and the SEM photograph illustrate that the layers of MMT were delaminated and all samples are of the anatase phase. The XPS survey spectrum confirms that TiO2 was successfully doped with N and S. The BET results show that all samples have a large surface area and mesopore structure. The photocatalytic activities of NST–MMT photocatalysts for degradation acid red G (ARG) are higher than that of undoped TiO2–montmorillonite (TPLM). The catalyst obtained at 350 °C is with the highest photocatalytic activity.

The nanometer potassium niobate powders with tungsten bronze (TB)-type structure were synthesized by a wet chemical method and characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). X-ray photoelectron spectroscopy (XPS) analysis confirmed the niobium with mixed valence states exists in the crystal structure of the photocatalyst, which may be advantage for increasing the photocatalytic activity. The band gap of K6Nb10.8O30 powders was estimated to be about 2.92eV and shows a markedly blue-shift as compared to that of the sample obtained by the solid-state reaction. The photocatalytic activity of the samples was evaluated by degradation of acid red G under UV irradiation and the photocatalytic reaction follows first-order kinetics. The photocatalytic activity of the as-prepared sample is much higher than that of sample synthesized by solid-state reaction, and slightly higher than that of P25-TiO2.

The photocatalytic activities of nitrogen and sulfur codoped TiO2 pillared montmorillonite (N,S-TiO2-PILM) for the degradation of 4BS dye under visible-light irradiation (λ >400nm) were studied. The catalysts were synthesized by impregnating doped titania sol into the interlayer of montmorillonite (MMT) and characterized by the UV−vis diffuse reflectance spectra, transmission electron microscopy, and the FT-IR absorption spectra. The ordered structure of MMT was destroyed to some extent and the size of TiO2 particles is about 2−6 nm. The absorption edge of the doped samples shows a red-shift as compared to that of pure TiO2. The photocatalyic activity of N,S-TiO2-PILM with a mole ratio of Ti:S of 1:4 and obtained at 350 °C for 2 h is higher than that of the other samples and Degussa P25 under visible light irradiation. The chromophore in the molecular structure of 4BS was destroyed completely by the photocatalytic reaction and the naphthalene rings and benzene rings were also decomposed partly.

The compound Sr10Bi6O24−y doped with Ni was prepared by solid-state reaction method. The obtained powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectra and X-ray photoemission spectra (XPS). The Ni-doped Sr10Bi6O24−y samples assume a cubic perovskite structure with space group Fm3m (225). Bi in Sr10Bi6O24−y exists in the valence state of Bi(II). Photocatalytic activities of the prepared samples were evaluated using acid red G as a model organic compound. The results show that doping with 0.5wt.% Ni can significantly improve the photoactivity of the compound Sr10Bi6O24−y.

This study involves laboratory preparation of perovskite-type Sr10Bi6O24-y, which is characterized by a series of instruments such as XRD, SEM and XPS, and photodegradation of Acid Red G, a dyestuff, with Sr10Bi6O24-y as the photocatalyst. The experiment shows its presence greatly enhances degradation reaction.