| TiO2/Gd2O3纳米粉体的制备、表征及光催化活性 | |
| Preparation, Characterization and Photocatalytic Activities of TiO2/Gd2O3 | |
| 摘要: 利用酸催化的溶胶-凝胶法制备了纯TiO2和Gd3+(0.5wt%)掺杂的TiO2纳米粉体，采用XRD、BET、XPS、紫外-可见漫反射谱(DRS)和表面光电压谱(SPS)等技术进行了表征；以亚甲基蓝(MB)的光催化降解为探针反应，评价了其光催化活性；探讨了Gd3+掺杂对TiO2纳米粉体的光催化活性的影响机制。结果表明，TiO2/Gd2O3纳米粒子对MB溶液的光催化活性提高到纯TiO2的1.5倍。掺杂Gd3+可以强烈抑制TiO2由锐钛矿相向金红石相的转变；阻碍TiO2晶粒的生长；提高高温组织稳定性，改善粉体的表面织构特性；形成光生电子的浅势捕获陷阱，抑制e-/h+复合，这些因素共同作用最终导致TiO2/Gd2O3纳米粉体的光催化活性明显提高。XPS分析结果证实，掺杂Gd3+导致粉体的表面羟基含量降低。由于产生了量子尺寸效应，复合粉体的紫外吸收带边蓝移，光的吸收能力略有降低。 | |
| 关键词: 纳米TiO2 Gd3+掺杂 光催化活性 环境净化 | |
| 基金项目: | |
| Abstract: Pure TiO2 and 0.5wt% Gd3+-doped TiO2 composite nano-particles were prepared by an acid-catalyzed sol-gel method and characterized by XRD, BET, XPS, UV-Vis diffuse reflectance spectroscopy (DRS) and surface photovoltage spetrum (SPS) techniques. The photocatalytic degradation of methylene blue in aqueous solution was used as a probe reaction to evaluate the photocatalytic activity of the synthesized nano-particles. The mechanism of effects of Gd3+-doping on the photocatalytic activity of TiO2 nano-particles was also discussed. The results show that the photocatalytic activity of TiO2/Gd2O3 composite nano-particles is 1.5 times as high as that of pure TiO2. The presence of Gd3+ can inhibit the phase transformation from anatase to rutile, suppress the growth of the crystal grains, raise the specific surface area, improve the high temperature stabilization of pores in the composite nano-powders, form the capture traps of the photoproduced electron to inhibit their recombination, resulting in the enhancement of the photocatalytic activity of TiO2/Gd2O3 nano-powders. The results of XPS analysis confirm that Gd3+-doping can lead to the decrease in density of hydroxyl groups on the particle surface. For the composite nanoparticles, a quantum size effect appears, resulting in a blue shift of the absorption edge and a slight decrease in the capability of light absorption. | |
| Keywords: nanosized titania Gd3+-doping photocatalytic activity environmental cleaning | |
| 摘要点击次数: 1714 | |
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| 姜洪泉,王鹏,卢丹丹,吴兰英,线恒泽.TiO2/Gd2O3纳米粉体的制备、表征及光催化活性[J].无机化学学报,2006,22(1):73-78. | |
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