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Photocatalytic Activity for Water Decomposition to Hydrogen over Nitrogen‐doped TiO 2 Nanoparticle
Author(s) -
LI XiaoBo,
JIANG XiaoYing,
HUANG JianHua,
WANG XueJing
Publication year - 2008
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200890385
Subject(s) - photocatalysis , anatase , x ray photoelectron spectroscopy , chemistry , rutile , dopant , catalysis , nanoparticle , visible spectrum , annealing (glass) , hydrogen , water splitting , photochemistry , inorganic chemistry , doping , chemical engineering , nanotechnology , materials science , organic chemistry , optoelectronics , engineering , composite material
Nitrogen‐doped TiO 2 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 °C. XPS studies indicate that the nitrogen atom enters the TiO 2 lattice and occupies the position of oxygen atom. Agglomeration of particles is found in TEM images after annealing. BET results show that the specific surface areas of N‐doped samples from 44.61 to 38.27 m 2 /g are smaller than that of Degussa TiO 2 . 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 condition on the photocatalytic property has been researched over water decomposition to hydrogen, indicating that nitrogen raises the photocatalytic activity for hydrogen evolution, and the modified TiO 2 annealed for 2 h at 400 °C under gas of NH 3 /N 2 ( V / V =1/2) mixture shows better efficiency of hydrogen evolution. Furthermore, the N‐doped TiO 2 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 reference and the N‐doped TiO 2 annealed at 700 °C.