Er3+掺杂TiO2空心球的制备及其光催化性能研究

以钛酸四丁酯、氧化铒、硝酸等为原料, 采用碳球模板法制备了TiO₂: Er³⁺空心球材料, 利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)等测试方法, 对样品的结构和形貌进行了表征。并利用紫外-可见(UV-Vis)分光光度计考察了TiO₂: Er³⁺空心球材料在催化染料罗丹明B、亚甲基蓝、茜素红、甲基橙的脱色降解过程中的应用性能。系统研究了Er³⁺掺杂浓度、不同离子型染料和染料水溶液的pH等因素对催化降解效率的影响。实验结果表明: 经600℃煅烧3 h制备的TiO₂: Er³⁺为锐钛矿晶型, 空心球结构, 尺寸均匀, 粒径约为120 nm, 比表面积约为60.5 m²/g; Er³⁺掺杂量为0.5mol%的样品对甲基橙染料的催化降解效率最高; 对四种不同离子型染料, 茜素红的催化降解效果显著, 在紫外光照射下, 催化效率较未掺杂Er³⁺的TiO₂提高了约30%。

Preparation of TiO2: Er3+ Hollow Spheres and Its Photocatalytic Properties

Using tetrabutyl titanate, erbium oxide and nitric acid as raw materials, TiO₂: Er³⁺ hollow spheres were prepared with carbon spheres as template. The structures and morphologies of the obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). The photocatalytic activities were studied by degradation of organic pollutants (rhodamine B, methylene blue, alizarin red, methyl orange) using UV-Vis spectrophotometer. The factors, such as Er³⁺ dopant concentration, pH of the dye solution, on the photocatalytic activities were discussed. The results showed that uniform and well crystallized TiO₂: Er³⁺ hollow spheres in an anatase phase, with diameter of 120 nm could be obtained via carbon-template method followed by a heat treatment at 600℃ for 3 h. The specific surface area of the TiO₂: Er³⁺ hollow spheres was about 60.5 m²/g. When the Er³⁺ dopant concentration was 0.5 mol% of Ti⁴⁺ ions in TiO₂, the photocatalytic activity of catalyst on the methyl orange was better than the other samples. Among the four different organic pollutants, the photocatalytic activity on the alizarin red was best. TiO₂: 0.5mol%Er³⁺ showed the better photocatalytic properties than the undoped TiO₂. The photodegradation efficiency of alizarin red with TiO₂: 0.5mol%Er³⁺ was 30% higher than that with the undoped TiO₂ under UV light irradiation.