Ce-TiO_(2)粉体的制备及其光催化性能研究

Preparation of Ce-TiO_(2) Powder and Its Photocatalytic Performance Research

以钛酸丁酯为前驱体,采用溶胶-凝胶法制备Ce掺杂纳米TiO_(2)。结合XRD、TEM、UV-Vis等现代检测手段对所制备样品的结构和性能进行表征。以直接桃红12B为目标降解产物,考察了所制备样品的光催化活性。研究结果表明:样品在550℃煅烧后,TiO_(2)为锐钛矿型,Ce掺杂纳米TiO_(2)后晶粒尺寸由23.9 nm降低到19.8 nm。Ce掺杂引起TiO_(2)的光学吸收边红移,提高可见光的吸收,拓展了TiO_(2)光谱响应范围。催化剂投加量为0.5 g/L,直接桃红12B溶液的初始浓度为20 mg/L,pH值为5。在紫外光下2 h条件下,Ce掺杂TiO_(2)后去除率由83.6%提高到93.8%。低浓度下的光催化降解过程可用Langmuir-Hinshelwood一级动力学方程拟合,初始浓度20 mg/L时,吸附速率可达到0.06304 min^(-1)。

Using butyl titanate as precursor,Ce-doped nano TiO_(2) is prepared by sol-gel method.The structure and performance of the synthesized samples are characterized by means of X-ray diffraction,transmission electron microscopy,and ultraviolet-visible and so on.The photocatalytic activity of the samples is investigated by the degradation for straight pink 12B.The results show that the main crystalline phase of Ce-TiO_(2) calcined at 550℃is anatase,the particle size decreasing from 23.9 nm to 19.8 nm.Ce doping causes the red shift of the optical absorption edge of TiO_(2),improves the absorption of visible light,and expands the spectral response range of TiO_(2).When the dosage of catalyst is 0.5 g/L,the initial concentration of straight pink 12B solution is 20 mg/L,pH value is 5,and under UV light for 2 h,the removal rate of Ce-TiO_(2) increases from 83.6%to 93.8%.The photocatalytic degradation process at low concentration can be fitted by Langmuir-Hinshelwood first-order kinetic equation.When the initial concentration is 20 mg/L,the adsorption rate reaches 0.06304 min^(-1).