3DOM La_(0.4)Ce_(0.6_)FeO_(3)可见光催化剂的制备及非均相光芬顿催化协同降解亚甲基蓝

Preparation of 3DOM La_(0.4)Ce_(0.6_)FeO_(3)visible light photocatalyst and heterogeneous photo-Fenton catalytic synergistic degradation of methylene blue

以聚苯乙烯微球为模板,采用模板法联合溶胶-凝胶法制备了三维有序大孔(3DOM)材料La_(0.4)Ce_(0.6_)FeO_(3)(记作3DOM La_(0.4)Ce_(0.6_)FeO_(3)),并对其进行了表征。以亚甲基蓝为模型污染物,研究了3DOM La_(0.4)Ce_(0.6_)FeO_(3)的催化性能、稳定性和催化反应机理。实验结果表明,3DOM La_(0.4)Ce_(0.6_)FeO_(3)呈现3DOM结构,丰富的孔道和较大的比表面积增强了光的捕获与传质,Ce掺杂使Fe^(2+)含量增加;与均相光催化剂相比,3DOM La_(0.4)Ce_(0.6_)FeO_(3)具有更广的pH适用范围、更低的铁泥产量及更高的双氧水利用率;重复使用5次后,3DOM La_(0.4)Ce_(0.6_)FeO_(3)对亚甲基蓝的降解效率维持在较高水平,表明催化剂稳定性较强;猝灭实验和ESR测试结果表明,亚甲基蓝的降解是在·OH和·O_(2)-共同作用下完成的;结合XPS等分析结果提出了3DOM La_(0.4)Ce_(0.6_)FeO_(3)非均相光芬顿与光催化协同降解亚甲基蓝的机理。

Three-dimensional ordered macroporous(3DOM)La_(0.4)Ce_(0.6_)FeO_(3) were synthesized using polystyrene microspheres as templates by template method combined with sol-gel method and characterized.Using methylene blue as a model pollutant,the catalytic performance,stability and catalytic reaction mechanism of 3DOM La_(0.4)Ce_(0.6_)FeO_(3)were studied.The results demonstrated that the 3DOM La_(0.4)Ce_(0.6_)FeO_(3)presented a 3DOM structure.The abundant channels and large specific surface area enhanced the light capture and mass transfer,and Ce doping increased the Fe^(2+) content.3DOM La_(0.4)Ce_(0.6_)FeO_(3) had a wider pH range than homogeneous catalysts,lower iron sludge output and higher hydrogen peroxide utilization.After 5 cycles,the degradation efficiency of 3DOM La_(0.4)Ce_(0.6_)FeO_(3)on methylene blue was maintained at a relatively high level,indicating that the catalyst was more stable.The quenching experiment and ESR test results indicated that the degradation of methylene blue was completed under the combined action of·OH and·O_(2)-.Combining the analysis results of XPS and other analysis results,the mechanism of 3DOM La_(0.4)Ce_(0.6_)FeO_(3)heterogeneous photo-Fenton and photocatalysis for synergistic degradation of methylene blue was proposed.