焙烧时间对钛酸钙光催化性能的影响

Effect of baking temperature on photocatalytic properties of titanium calcium

以CaCO3和TiO2为原料,焙烧温度为1500℃,焙烧时间分别为2、4、6、8、10h的条件下焙烧得到CaTiO3。应用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外变换光谱仪(FT-IR)、紫外-可见光漫反射光谱仪(UV-Vis)对焙烧后的物料进行了表征。实验结果表明,焙烧时间对合成CaTiO3的纯度影响很小;焙烧时间的延长使得CaTiO3微观形貌从不规则多边形向光滑曲面形变化,颗粒团聚现象越来越明显,堆积密实,尺寸增大;焙烧时间对钛酸钙光吸收能力的影响很小。在光催化性能评价实验中,随着焙烧时间的延长,亚甲基蓝的降解率和降解速率降低,反应速率常数最多可降低接近50%;钛酸钙降解亚甲基蓝溶液比较符合一级反应动力学特征。

CaCO3 and TiO2 used as raw materials were baked to obtain CaTiO3 in the conditions that baking time is respectively 2,4,6,8 and 10 hat 1500℃.The materials treated under high-temperature were characterized by XRD,SEM,FTIR,UV-Vis.The results show that baking time affects little on the synthesis of CaTiO3;with the time and temperature increasing,morphology of synthetic CaTiO3 changes into the smooth surface shape from irregular polygon-shape,and particles reunion phenomenon is increasingly apparent,and accumulation is dense among particles and size of particles increases.Baking time has little effect on the light absorption capacity of CaTiO3.With the extension of baking time in experiments of photocatalytic performance evaluation,the degradation rate and speed of methylene blue all reduces,and reaction rate constant can reduce the nearly 50%.The degradation of CaTiO3 on methylene blue solution is in line with a kinetic characteristic.