可见光下掺Fe^(3+)A-TiO_2粉体对茜素红的催化降解

Catalytic degradation of alizarin red by Fe^(3+)-doping A-TiO_2 powder under visible light

用水热法制备了(掺杂)TiO_2粉体试样,利用红外光谱仪(FT-IR)、X射线衍射(XRD)和扫描电子显微镜(SEM)对产物进行了表征。探索在可见光下用(掺杂)TiO_2催化降解茜素红的效果,研究茜素红初始浓度、pH、催化剂用量、掺Fe^(3+)量、光照时间等因素的影响。结果表明:试样中出现3400、1636 cm^(-1)的吸收峰,说明它含有大量—OH;粉体为锐钛矿型即为A-TiO_2;试样由诸多细小的纳米晶定向聚集生成,八面体型纳米晶呈现复杂3D花状结构,花状结构的直径2.5μm左右,纳米晶体的长度1～1.5μm,形成八面体晶体的三角形边长100～200 nm;TiO_2光催化降解茜素红的最佳条件:茜素红溶液初始浓度1.5 g·L^(-1)、调节溶液的pH为4.0、自制掺Fe^(3+)量5%(摩尔分数)的A-TiO_2用量0.502 g·L^(-1)、恒温14℃、60 W白炽灯,光照时间45 min,茜素红降解率87.22%。用自创技术制备的掺杂TiO_2粉体有较高的光催化性能。

(Fe^3+-doping)TiO 2 powder was prepared via hydrothermal method and was characterized by fourier transform infrared spectrometer(FT-IR),X-ray diffraction(XRD),and scanning electronic microscope(SEM)technologies.The catalytic degradation of alizarin red on(Fe 3+-doping)TiO 2 under visible light was studied.The effects of initial concentration of alizarin red,initial pH of alizarin red solution,catalyst dosage,doping amount of Fe 3+ and illumination time on the degradation of alizarin red were explored.The results showed that the sample contains a large number of-OH groups corresponding to the absorptions of 3400 and 1636 cm -1 .XRD determined that the samples'crystal is anatase i.e.A-TiO 2;SEM showed that the samples have a complex 3D flower-like structure,the formation of octahedron nanocrystals is composed of nanocrystalline orientation and aggregation.Diameter of the flower-like TiO2 nanostructure is 2.5 μm,and the individual TiO 2 nanocrystal is shown in octahedron and has triangle planes with 100~200nm in side and 1~1.5μm in length.The degradation rate of alizarin red is 87.22%under the following optimizing conditions:the initial concentration of alizarin red is 1.5 g·L^-1 ,the solution's pH=4.0,the dosage of Fe 3+-doping TiO2 is 0.502 g·L ^-1 ,the amount of doping-Fe 3+ is 5%(molar fraction)and the illumination time is 45 min under visible light(60 W incandescent lamp)at constant temperature 14℃.The Fe^3+-dopingTiO 2 powder prepared by self-made technology had a higher photocatalytic performance.