层状氧化物NaCo_2O_4热催化H_2O_2降解亚甲基蓝

采用固相烧结法制备了NaCo_2O_4催化剂,构建了NaCo_2O_4-H_2O_2热催化体系降解亚甲基蓝(MB)。XRD和SEM表征结果显示,合成的NaCo_2O_4催化剂具有良好的稳定性。NaCo_2O_4对H_2O_2具有良好的热催化性能,反应温度越高,反应速率常数k越大,该催化反应符合一级动力学方程。NaCo_2O_4-H_2O_2体系对MB具有较好的降解效果,在反应温度为50℃、NaCo_2O_4加入量为50 mg、MB溶液加入量为100 mL、MB初始质量浓度为30 mg/L、H_2O_2加入量为1.00 mL的最优条件下,反应340 min时,MB降解率达87.00%;催化剂重复使用三次,MB降解率仍可达85%以上;经捕获剂效果对比实验发现,催化反应体系中存在h~+、·OH等催化活性物种。

Degradation of methylene blue with H2O2 thermo-catalyzed by layered oxide NaCo2O4

The NaCo₂O₄ catalyst was prepared by solid phase sintering method. The NaCo₂O₄-H₂O₂ thermo-catalytic system was built for degradation of methylene blue（MB）. The characterization results of XRD and SEM showed that the prepared NaCo₂O₄ catalyst had good stability. NaCo₂O₄ had exhibited an excellent thermo-catalytic activity on H₂O₂. The reaction rate constant k increased with the increase of reaction temperature,and the catalytic reaction accorded with the first order kinetic equation. The NaCo₂O₄-H₂O₂ system had good effect on degradation of MB,and the degradation rate of MB reached 87.00 % under the optimum conditions of reaction temperature 50 ℃,NaCo₂O₄ amount 50 mg,MB amount 100 mL,initial MB mass concentration 30 mg/L,H₂O₂ amount 1.00 mL and reaction time 340 min;After 3 times of reuse of the catalyst,the degradation rate of MB was still above 85%;It was confirmed by scavenger test that there were active species such as h⁺ and ·OH hole in the catalytic reaction system.