焙烧温度对钛酸钙光催化性能的影响

Effect of Baking Temperature on Photocatalytic Properties of Calcium Titanate

以CaCO3和TiO2为原料,分别在1 100,1 200,1 300,1 400,1 500℃条件下进行焙烧.应用XRD,SEM,FT-IR,UV-vis对处理后的物料进行表征.实验结果表明,1 400℃以上能够合成出纯CaTiO3;随着温度提高,颗粒微观形貌从不规则多边形向光滑曲面形变化,团聚现象趋于明显;CaTiO3和TiO2含量不同导致催化剂在紫外-可见光区域光吸收能力有较大不同.在光催化性能评价实验中,随着温度提高,亚甲基蓝降解率和降解速率均降低,反应速率常数降低幅度达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.

With CaCO3 and TiO2 as raw materials,they were separately baked at 1 100,1 200,1 300,1 400 and 1 500 ℃,and then characterized by XRD,SEM,FT-IR,UV-vis.The results showed that the high-purity CaTiO3 can be synthesized above 1 400 ℃.With the temperature increasing,the micro morphology of synthesized CaTiO3 surface changes from irregularly polygonal to smooth,and the agglomeration of particles tends to be apparent.The different contents of CaTiO3 and TiO2 lead the absorbance of catalyst to be greatly different in UV-visible region.As the experimental results of photocatalytic performance evaluation,the degradation rate and efficiency of methylene blue both decrease with temperature increasing,and the reaction rate constant decreases by 50%.The degradation of the methylene blue with calcium titanate is comparatively in line with the characteristics of first-order reaction kinetics.