通过水热法制备了铁掺杂TiO₂催化剂,采用X射线衍射仪、傅里叶变换红外光谱仪、扫描电子显微镜对其结构和形貌进行了表征,研究了催化剂在可见光照射下对铬天青S溶液的催化效果。结果表明:粉末状催化剂晶体为纯锐钛矿型TiO₂;1600cm^-1、3730cm^-1附近出现的吸收峰说明催化剂中含有大量—OH,预示催化剂具有良好的光催化活性;催化剂由大量微小的纳米晶体定向聚集形成复杂的三维花状结构,每个纳米晶呈八面体型。掺杂铁离子有助于提高催化剂的光催化效率,铁离子掺杂量为3%(摩尔分数,下同)时,催化剂光催化活性最好,光照65min时其光催化效率比纯锐钛矿型TiO₂催化剂提高12.9%。通过实验得出光催化降解的优化条件:铬天青S溶液初始质量浓度为20mg/L、溶液pH=4、铁离子掺杂量为3%、催化剂用量为0.6g/L、室温25℃、40W白炽灯为光源、光照时间65min。在优化条件下,铬天青S降解率达到87.1%。

Iron doped TiO₂ catalyst was prepared via hydrothermal method and characterized by X-ray diffraction(XRD),fourier transform infrared spectrometer(FT-IR) and scanning electronic microscope(SEM) technologies.The catalytic effect of modified TiO₂ powder on chrome azurol S was studied under visible light irradiation.The results shown that the powder crystal was pure anatase type TiO₂.The absorption peaks around 1600cm^-1 and 3730cm^-1 indicated that the catalyst contained a large amount of —OH,which meant they will possess better photo-catalytic performance.The powder consists of a large number of tiny nanocrystals which formed a complex 3D flower-like structure and each nanocrystal was octahedral.The photocatalytic efficiency of the product was improved by iron doping,and the photocatalytic activity of the product was the best when the molar amount of iron-doping was 3%,the photocatalytic efficiency of the product increased by 12.9% when the irradiation time was 65min compared with that of pure anatase-TiO₂.Under following optimizing conditions:the initial concentration of chrome azurol S was 20mg/L,the pH of the solution was adjusted to 4,the iron-doping TiO₂ dosage was 0.6g/L,the iron-doping amount was 3% (molar fraction) and the illumination time was 65min under visible light (40W incandescent lamp) at room temperature 25℃,the degeneration rate of chrome azurol S reached 87.1%.