Cu-Mg-Ce复合氧化物活化过硫酸钠降解罗丹明B

Activation of Sodium Persulfate by Cu-Mg-Ce Composite Oxides for Degradation of Rhodamine B

利用共沉淀法制备Cu-Mg-Ce复合氧化物,比较不同体系活化过硫酸钠(PS)对罗丹明B的去除效果,考察催化剂投加量、氧化剂PS浓度、底物初始质量浓度、溶液初始pH对罗丹明B去除的影响.结果表明:Cu-Mg-Ce复合氧化物投加量为1.0 g/L、PS浓度为1 mmol/L、底物初始质量浓度为10 mg/L时,罗丹明B的最高去除率可达99.47%;Cu-Mg-Ce/PS体系可有效降解罗丹明B的初始质量浓度范围为5~20 mg/L,pH范围为5~7.Cu-Mg-Ce复合氧化物具有良好的稳定性,循环使用5次后,罗丹明B的去除率>97%.Cu-Mg-Ce复合氧化物活化PS的机理推演证明,Cu与Ce具有协同作用,反应过程中发生电子转移,催化剂中Ce^(3+)/Ce^(4+)、Cu^(2+)/Cu^(+)之间进行转化产生Cu^(+),进而活化PS形成SO_(4)^(-),有效降解罗丹明B.

In our study Cu-Mg-Ce composite oxide was prepared with the use of a co-precipitation method,the effects of different systems on the removal of rhodamine B by activated sodium persulphate(PS)were compared,and the effects of catalyst dosing,PS concentration,initial rhodamine B concentration and initial pH of the solution on the removal of rhodamine B were investigated.The results of our study showed the highest removal rate of rhodamine B was 99.47%at Cu-MgCe composite oxide dosage of 1.0 g/L,PS concentration of 1 mmol/L and initial rhodamine B concentration of 10 mg/L.The Cu-Mg-Ce/PS system could effectively degrade rhodamine B in the initial concentration range of 5-20 mg/L and pH range of5-7.The Cu-Mg-Ce composite oxide had good stability and the rhodamine B removal rate was>97%after 5 cycles.The principle deduction of Cu-Mg-Ce composite oxide activation of PS demonstrates that Cu and Ce have a synergistic effect,with electron transfer occurring during the reaction and conversion between Ce^(3+)/Ce^(4+) and Cu^(2+)/Cu^(+) in the catalyst to produce Cu^(+),which in turn activates PS to form SO_(4)^(-) for effective degradation of rhodamine B.