Photocatalytic Activity for Water Decomposition to Hydrogen over Nitrogen-doped TiO2 Nanoparticle

• 来源期刊: 中国化学(英文版)
• 年，卷（期）: 2008,（12）
• 页码范围: 2161-2164
• 页数: 4页
• 语种: 英文

摘要

Nitrogen-doped TiO2 nanoparticle photocatalysts were obtained by an annealing method with gaseous ammonia and nitrogen. The influence of dopant N on the crystal structure was characterized by XRD, XPS, BET, TEM and UV-Vis spectra. The results of XRD indicate that, the crystal phase transforms from anatase to rutile structure gradually with increase of annealing temperature from 300 to 700 ℃. XPS studies indicate that the nitrogen atom enters the TiO2 lattice and occupies the position of oxygen atom. Agglomeration of particles is found in TEM im-ages after annealing. BET results show that the specific surface areas of N-doped samples from 44.61 to 38.27 m2/g are smaller than that of Degussa TiO2. UV-Vis spectra indicate that the absorption threshold shifts gradually with increase of annealing temperature, which shows absorption in the visible region. The influence of annealing condi-tion on the photocatalytic property has been researched over water decomposition to hydrogen, indicating that ni-trogen raises the photocatalytic activity for hydrogen evolution, and the modified TiO2 annealed for 2 h at 400 ℃ under gas of NH3/N2 (V/V= 1/2) mixture shows better efficiency of hydrogen evolution. Furthermore, the N-doped TiO2 nanoparticle catalysts have obvious visible light activity, evidenced by hydrogen evolution under visible light (λ>400 nm) irradiation. However, the catalytic activity under visible light irradiation is absent for Degussa as ref-erence and the N-doped TiO2 annealed at 700 ℃.