Preparation and application of S cation and N anion co-doped TiO_2 pillared montmorillonite nano composite photocatalyst

摘要

The S cation and N anion co-doped TiO_2 pillared montmorillonite nano composite photocatalyst has been synthesized, in which S cations substitute for some of the lattice titanium atoms and N anions replace some of the lattice oxygen atoms. The composite photocatalyst shows strong absorption for UV and visible light and high activities for degradation of a volatile matter, formaldehyde gas. The states of the S and N atoms incorporated into the TiO_2 particles are determined to be mainly S~(4+) and N~(2-) respectively from X-ray photoelectron spectra (XPS). The proofs from XRD patterns and TEM pictures demonstrate that the mean diameter of TiO_2 particles is less than 1nm. The absorption spectrum (range from 250～700nm) of TiO_2 suspension reveals strong absorbance in UV and visible light regions, and apparently, shows double absorption peaks at nearly 335 and 475 nm respectively.rnHaving been organically modified, the composite photocatalyst is homogeneously blended with a kind of plastic powder in a plastic kneader. Then, this mixture, so-called matrix is sprayed onto a plastic product surface by means of a special method. Irradiated by visible light, the degradation test concludes that the plastic product supported composite photocatalyst can effectively degrade the volatile formaldehyde gas.