摘要：

以金属硝酸盐为原料，采用溶胶凝胶法控制合成了Ce、Mn掺杂的钴基钙钛矿系列催化剂，通过XRD、SEM、TEM、XPS、EPR等方法探究了催化材料的结构特性，并以茜素红和酸性品红作为探针有机污染物，探究在氙气灯条件下的光催化降解性能，其茜素红和酸性品红降解率分别可达95%和90%以上，催化剂在循环使用6次后仍保持良好的降解稳定性。结果表明，Mn、Ce元素的引入促进了LaCoO₃基钙钛矿比表面积的增大，且在晶体结构中形成了更多结构缺陷，XPS、ERP及反应前后的红外测试结果表明材料结构中的氧空位缺陷可促使茜素红结构中的醌式结构瓦解，进而促进光催化降解性能提升。同时，表面氧物种及氧空位是主要的光催化降解有机污染物活性物种，LaCo_0.7Ce_0.3O₃因其适宜的结构性能而表现出最优的光催化降解性能。

关键词: 钙钛矿, 金属掺杂, 光催化降解, 有机污染物

Abstract:

Cobalt-based perovskite catalysts doped with Ce and Mn were synthesized by sol-gel method using metal nitrate as raw materials. The structural properties of the prepared catalysts were investigated by XRD, SEM, TEM, XPS, EPR, etc. The photocatalytic degradation performance under xenon lamp conditions was investigated by using alizarin red and acid fuchsin as probe organic pollutants. The degradation rates of alizarin red and acid fuchsin could reach 95% and 90%, respectively, and the catalyst maintained good degradation stability after being recycled for 6 times. The results showed that the introduction of Mn and Ce elements increased the specific surface area of LaCoO₃-based perovskite, and more structural defects were formed in the crystal structure. XPS, ERP and infrared tests before and after the reaction showed that the oxygen vacancy defect in the material structure could promote the collapse of the quinone structure in the red structure of the material, and further improved the photocatalytic degradation performance. At the same time, surface oxygen species and oxygen vacancy were the main active species for photocatalytic degradation of organic pollutants, and LaCo_0.7Ce_0.3O₃ showed the best photocatalytic degradation performance due to its suitable structural properties.

Key words: perovskite, metal doping, photocatalytic degradation, organic pollutants

中图分类号: 

• X703.1