Preparation of Fe Dopped BiOBr Using Different Bromine Source and Visible-light Photocatalytic Activity
LI Xin-yu;FANG Yan-fen;XIONG Shi-wei;JIA Man-ke;MA Wan-hong;HUANG Ying-ping;Collaborative Innovation Center for Geo-Hazards and Eco-Environment in Three Gorges Area,Hubei province,China Three Gorges University;China Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,China Three Gorges University;
Fe dopped BiOBr was synthesized via a facile hydrothermal method,where using sodium bromide(NaBr) and cetrimonium bromide(CTAB) as the raw materials. All the samples were characterized by using various methods including X-ray diffraction,Scanning electron microscopy,UV-Vis diffuse reflectance spectra and Fluorescence spectrophotometer,respectively. The result showed that in the same preparation conditions,Fe doped BiOBr could be gained when NaBr was used as bromine source,Fe entered into BiOBr crystal lattice and formed the new bounds of Bi-O-Fe or Br-O-Fe,iron content was approximately 0. 20 by EDS,the band gap was 1. 92 eV. PL analysis showed that Fe doped BiOBr helps reduce recombination rate of photoproduction hole and photoproduction electronic. However,we got merely pure BiOBr when CTAB was used as bromine source,XPS and EDS detection of ferric content of only 0. 07,the band gap was 2. 78 eV. Samples were named F0. 2-BiOBr and Fe0-BiOBr according to the content of Fe. It was indicated that Fe0. 2-BiOBr(k = 0. 109 min-1) had the better photocatalytical activity than Fe0-BiOBr(k = 0. 055 min-1) under visible light(λ≥420 nm) degradation of Rhodamine B(RhB). The samples were proved to be an efficient and relatively stable photocatalyst under six recycling experiments. It was indicated that the visible-light photocatalytic activity of Fe0. 2-BiOBr was attributed by both crystal lattice iron and surface iron oxides by the Electron spin resonance results and free radical scavenging experiments. Fe 3d orbitals was involved the formation of valence band(VB) and conduction band(CB) of Fe-BiOBr and superoxide radical(O2·-) and valence band hole(h+) acted as the main reactive oxygen species.