蛋白土为载体二氧化钛光催化材料制备与表征

Preparation and characterization of titanium dioxide photocatalytic material with opal as carrier

以蛋白土作为二氧化钛光催化材料的矿物载体,使用四氯化钛作为钛源,采用水解沉淀法制备二氧化钛光催化材料。以降解罗丹明B为考察指标,采用单因素实验考察了煅烧温度、煅烧时间、二氧化钛负载量对光催化材料性能的影响,采用正交实验考察了其他因素对光催化材料性能的影响。蛋白土负载二氧化钛较优制备条件:煅烧温度为600℃、煅烧时间为120 min、二氧化钛负载量为20%(质量分数)、反应温度为40℃、钛离子与硫酸根物质的量比为1∶2、氨水质量分数为20%、矿浆质量分数为5%、氨水滴加速度为4 m L/min。同时对光催化材料进行扫描电镜(SEM)和X射线衍射(XRD)分析。SEM表征结果表明,蛋白土表面有二氧化钛附着,但是二氧化钛无法进入蛋白土孔径中,影响光催化效率,实验还有改进的空间。XRD表征结果表明,二氧化钛主要以锐钛矿的形式负载在蛋白土表面,样品XRD谱图中有明显的锐钛矿衍射峰,同时还有少量其他形式如金红石相存在。

The TiO2 photocatalytic composite materials were prepared by hydrolysis precipitation process with opal as carrier,and Ti Cl4 as titanium source.Taking the degradation rate of Rhodamine B as the investigated index,the influences of calcination temperature,calcination time and TiO2 loading on photocatalytic properties were investigated by single factor experiments.The influence of other factors on photocatalytic properties was investigated by orthogonal experiment.The optimal preparation conditions of opal/TiO2 photocatalyst were obtained： calcination temperature of 600 ℃,calcination time of 120 min,TiO2 loading amount of 20%（mass fraction）,reaction temperature of 40 ℃,the amount-of-substance ratio of Ti4＋to SO42-was 1∶2,the ammonia mass fraction of 20%,the mineral slurry mass fraction of 5%,and ammonia dropping rate of 4 m L/min.The opal/TiO2 photocatalyst was also characterized by SEM and XRD.SEM results showed there were TiO2 on the surface opal,but TiO2 could not enter the pores of the opal,which affect the photocatalytic efficiency.Therefore,the experiment still had improved space.The XRD showed that TiO2 was mainly loaded on the surface of opal in the form of anatase,and there was a siginficant anatase phase in the XRD map,and there were a few other forms,such as rutile phase.