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以溶胶-凝胶法制备纯的和分别掺杂Fe3+、Ce3+的TiO2纳米粒子,以橙黄IV的光催化氧化评价纳米粒子的紫外光与可见光活性,利用TG-DSC、XRD、BET及UV-Vis吸收光谱考察掺杂对TiO2的相变、粒径、比表面积及光吸收性能的影响,在归一化条件下探讨Fe3+及Ce3+掺杂对TiO2活性和表面性质产生影响的机制。结果表明:Fe3+及Ce3+的最佳掺杂量分别为0.2%和0.04%;Ce3+抑制TiO2由锐钛矿向金红石转变以及改善TiO2高温组织稳定性的能力均明显大于Fe3+;Fe3+和Ce3+掺杂均能提高TiO2的紫外光活性并扩展TiO2的光响应范围,但光生电子与空穴复合以及光腐蚀使它们对TiO2可见光活性的提高并不显著。Fe3+和Ce3+的半径及其相应氧化物的性质决定了两者对TiO2性能的不同影响。
The pure and doped Fe3 +, Ce3 + TiO2 nanoparticles were prepared by sol-gel method. The UV-Vis and visible light activity of the nanoparticles were evaluated by the yellow-orange IV photocatalytic oxidation. The properties of the nanoparticles were evaluated by TG-DSC, The influence of doping on the phase transition, particle size, specific surface area and light absorption property of TiO2 was investigated by absorption spectroscopy. The mechanism of the effect of Fe3 + and Ce3 + doping on the activity and surface properties of TiO2 was discussed under the normalized conditions. The results show that the optimum doping amounts of Fe3 + and Ce3 + are 0.2% and 0.04%, respectively. The ability of Ce3 + to inhibit the transformation from anatase to rutile and the high temperature stability of TiO2 are obviously higher than that of Fe3 + Can increase the UV activity of TiO2 and expand the photoresponse range of TiO2. However, the recombination of photogenerated electrons with holes and the photo-etching make them not significant to increase the visible light activity of TiO2. The radius of Fe3 + and Ce3 + and the nature of their corresponding oxides determine the different effects of both on the TiO2 properties.