氮掺杂TiO_2中空复合微球的制备及可见光光催化性能

为了提高TiO2的可见光光催化性能,以微米级聚苯乙烯微球为模板,钛酸四丁酯为前驱体,三乙胺为氮源,采用静电吸附自组装法制备了粒径为1.20μm、壳层的厚度约为30nm且球形形貌良好的氮掺杂TiO2中空复合微球,采用SEM、XPS、XRD和紫外-可见分光光度计研究了其结构及光催化性能。结果表明:氮进入TiO2晶格内取代了部分O并改变了晶格中Ti和O的化学状态,但对TiO2晶型结构没有明显影响;氮掺杂后的TiO2中空复合微球禁带宽度变窄,氮掺杂TiO2中空复合微球不仅在紫外区有较强的光吸收能力,在可见光区也表现出较强的光响应性,对甲基橙的光催化降解率较Degussa P25型纳米TiO2的明显增强。研究结果对TiO2在光催化领域的应用具有理论指导意义。

Preparation and visible-light photocatalytic property of nitrogen-doped TiO2 hollow composite microspheres

In order to improve the visible-light photocatalytic property of TiO₂, micrometer polystyrene microspheres were used as template, tetrabutyl titanate was used as precursor, and triethylamine was used as nitrogen source, electrostatic adsorption self-assembly method was applied to prepare the nitrogen-doped TiO₂ hollow composite microspheres with good spherical morphologies whose particle size was 1.20 μm and shell thickness was about 30 nm. The structure and photocatalytic properties were investigated with SEM, XPS, XRD and ultraviolet-visible spectrophotometer. The results show that the entrance of nitrogen into the TiO₂ lattice replaces parts of O and changes the chemical states of Ti and O in the lattice, but has no obvious effect on the crystal structure of TiO₂. The band gap of TiO₂ hollow composite microspheres after nitrogen-doping decreases, nitrogen-doped TiO₂ hollow composite microspheres not only have stronger light absorption ability in ultraviolet region, but also have stronger light response in visible region, the photocatalytic degradation rate of methyl orange is enhanced obviously compared with Degussa P25 nanometer TiO₂. The conclusion has theoretical guiding significance for the application of TiO₂ in photocatalysis research.