采用水解共沉淀法制备了稀土元素(La,Pr,Nd)掺杂量为0.5wt%~1.5wt%的TiO2光催化剂样本,并对其进行了XRD、TG-DTA、TEM、BET和UV-Vis表征。结果表明,所制备的TiO2光催化剂是以锐钛矿晶型为主的纳米颗粒,掺杂抑制了TiO2晶型由锐钛矿向金红石的转变,同时减小了晶粒尺寸、增大了比表面积、提高了吸光度,且使TiO2半导体的吸光范围发生了红移。将制得的TiO2光催化剂应用于溶液中草酸的降解反应,用K2MnO4滴定法分析降解效率,发现经掺杂改性后的TiO2样本光催化效率均有提高。其中,以掺杂量为1.0wt%的La掺杂样本具有最高的降解效率,与纯TiO2样本相比对草酸的降解率提高了近45%。
TiO2 doped with rare earth elements(La,Pr,Nd) was prepared by titanic chloride hydrolysis and coprecipitation method.The content of doped elements was varied from 0.5wt% to 1.5wt% with reference to mass fraction.The as-prepared TiO2 and the doped TiO2 were characterized by XRD,TG-DTA,TEM,BET and UV-Vis.The results show that pure TiO2 and doped TiO2 were the mixture of anatase and rutile,and the anatase was the main constituent;the doping hinders the crystal transformation and makes the TiO2 crystallite size smaller,the specific area larger,the light absorption increasing and the red shift of spectra of doped TiO2.The experiments of photocatalytic degradation of oxalic acid was used to investigate the activity of rare earth elements (La,Pr,Nd) doped TiO2 and their influence on the reaction process,the degradation rate of oxalic acid was evaluated by permanganimetric method.The degradation results show that the photocatalytic degradarion of oxalic acid by doped TiO2 increasing and TiO2 doped with rare earth element La expresses a higher photocatalytic activity and the optimum doping content was 1.0wt%,the photocatalytic degradation rate of oxalic acid was increased about 45% compared with the undoped TiO2.