Preparation of narrow band gap V_2O_5/TiO_2 composite films by micro-arc oxidation
Preparation of narrow band gap V_2O_5/TiO_2 composite films by micro-arc oxidation作者机构:State Key Lab of Material Processing and Dies & Mould Technology Huazhong University of Science and Technology Wuhan 430074 China National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology Nanchang Hangkong University Nanchang 330063 China
出 版 物:《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报(英文版))
年 卷 期:2012年第19卷第11期
页 面:1045-1051页
核心收录:
学科分类:080503[工学-材料加工工程] 0819[工学-矿业工程] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程(可授工学、理学学位)] 080502[工学-材料学]
基 金:the Open Research Fund of the National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology in Nanchang Hangkong University(No.gf200901002) the Analytical and Testing Center of Huazhong University of Science and Technology
主 题:composite films titanium dioxide vanadium pentoxide micro-arc oxidation sodium metavanadate rhodamine photocatalysis
摘 要:V2Os/TiO2 composite films were prepared on pure titanium substmtes via micro-arc oxidation (MAO) in electrolytes consisting of NaVO3. Their morphology and dements were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. Phase composition and valence states of species in the films were characterized by X-ray diffraction (XRD) and X-ray photoelec- tron spectroscopy (XPS). Ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS) were also employed to evaluate the photophysical property of the films. The VEOs/TiO2 composite films show a sheet-like morphology. Not only V205 phase appears in the films when the NaVO3 concentration of the electrolyte is higher than 6,10 g/L and is loaded at the surface of anatase, but also V4+ is incorporated into the crystal lattice of anatase. In comparison with pure TiO2 films the V2Os/TiO2 composite films exhibit significantly narrow band gap energy. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the narrowest band gap energy, which is approximately 1.89 eV. The V2Os/TiO2 composite films also have the significantly enhanced visible light photocatalytic activity. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the best photocatalytic activity and about 93% of rhodamine is degraded after 14 h visible light radiation.