Nd2O3／TiO2光催化剂的光生羟基自由基和光活性

以硝酸钕和钛酸四正丁酯作为前驱体,采用溶胶-凝胶法制备了Nd2O3/TiO2纳米光催化剂,并通过XRD和BET等手段进行了表征.以对苯二甲酸作为探针分子,结合化学荧光技术研究了光催化剂表面羟基自由基的生成;并以甲基橙为光催化降解反应模型化合物,考察了光催化剂的活性.测定了甲基橙在TiO2和Nd2O3/TiO2(1.0%)光催化剂上的吸附常数.结果表明:Nd2O3掺杂使TiO2的粒径减小,比表面积增大;羟基自由基的生成速率越大,催化剂的催化活性越高.Nd2O3掺杂有利于反应底物在催化剂表面的吸附,Nd2O3的最佳掺入量为Nd/Ti(摩尔比)=1.0%.

Photoinduced Hydroxyl Radicals and Photocatalytic Performance of Nd2O3/TiO2 Photocatalysts

Nd_2O_3/TiO_2 photocatalysts were prepared by sol-gel method using neodymium nitrate and tetrabutyl titanate as precursors,and characterized by means of XRD and BET.After the doped with Nd_2O_3,the particle diameter of catalyst was decreased,the specific surface area was increased,the formation rate of hydroxyl radical on the catalyst was increased,and the catalytic activity was improved.Using methyl orange as the model compound of the photocatalytic degradation reaction,the activity of the prepared photocatalysts was investigated in suspension irradiated by high-pressure mercury lamp;and the hydroxyl radical produced in the supernatant of the irradiated catalyst suspension containing terephthalic acid were also investigated by measuring the fluorescence derived by the reaction with terephthalic acid.As a result,the addition of Nd_2O_3 to TiO_2 notably enhanced its photocatalytic activity.The adsorption constants of methyl orange on the Nd_2O_3 doped catalysts and the nonmodified TiO_2 catalyst were evaluated,and the result showed the adsorption of methyl orange on the Nd_2O_3/TiO_2 catalysts was improved.The optimum loading amount of Nd ion is 1.0%(molar ratio).