The Preparation And Photocatalytic Performance Of Nitrogen Doped Titanium Dioxide Photocatalyst

Photocatalysis oxidation using TiO₂ semiconductor as catalyst is a new technology having the broad application prospect for environmental remediation as it may lead to complete mineralization of pollutants at ambient condition using the ultraviolet light as the energy source. However, the large scale application of titanium dioxide as photocatalyst is hampered by the fact that it can absorb only the very small ultraviolet part (3-4%) from solar light due to its wide band-gap of 3.2eV. An effective approach to shift the optical response of TiO₂ from the ultraviolet to the visible spectral range is to dope TiO₂ with nonmetal nitrogen element.In this paper, using butyl titanate (Ti⁴⁺) as titanium source, aniline (An) as nitrogen source, the PANI/TiO₂ precursors were prepared by the means of combining the sol-gel and in situ polymerization. The C series precursors (C-PANI/TiO₂) were firstly prepared by changing An:Ti⁴⁺ (PT)proportion, and then A series precursors (A-PANI/TiO₂) were prepared by changing pH value of the solution. Structures of two series precursors were characterized by FT-IR, XRD and SEM. The NC and NA series N-doping nano titanium dioxide photocatalysts were prepared by calcination of C and A series precursors, exploring the influence of the calcining temperature, the composition and structure of precursors on the structure and performance of photocatalyst, and studying the structure and spectrum performance of NC and NA series photocatalysts by FT-IR, XRD, SEM, TEM, XPS and UV-Vis. The photocatalysis performance of N-doping nano titanium dioxide was evaluated under irradiation of visible or ultraviolet light through photocatalysis experiment to MB.The results show that in PANI/TiO₂ precursor, the PANI and TiO₂ formed a kind of nano hybrid structure. It is also found that the N element from the thermal decomposition of PANI is incorporated into TiO₂ during calcining process of PANI/TiO₂ precursors, and formed TiO_2-xN_x, moreover there remain some carbon residues on TiO_2-xN_x granule.The photocatalysts presented shape of sphere and the granularity is about 10-50nm.The XPS...