Ag/MoO2/MWCNTs纳米复合材料的制备及其催化氧还原性能

Preparation and Catalytic Performance Investigation of Ag/MoO2/MWCNTs for Oxygen Reduction Reaction

采用水热法制备MoO2/MWCNTs,再通过紫外还原将银纳米颗粒沉积于其表面,成功制备了Ag/MoO2/MWCNTs复合材料。系统研究了合成条件对Ag/MoO2/MWCNTs的催化性能的影响。采用循环伏安法(CV)、线性扫描伏安法(LCV)及计时电流法(I-t)对Ag/MoO2/MWCNTs复合材料的电催化氧还原(ORR)性能及其催化氧还原稳定性进行了研究。结果表明,制备Ag/MoO2/MWCNTs的优选工艺条件为:合成MoO2/MWCNTs的反应温度为160℃,反应时间为6 h,MoO2(acac)2与MWCNTs的质量比为1∶1,AgNO3用量为200μL每1 mg MoO2/MWCNTs(20 mg·mL^-1)。优选条件下制备的Ag/MoO2/MWCNTs催化氧还原(ORR)为4电子催化过程,其起始电位为0.923 V,极限电流密度为6.34 mA·cm^-2,半波电位为0.81 V,经过15000 s后,催化活性仍高于90.5%。

MoO2/MWCNTs was prepared by hydrothermal method,and the Ag/MoO2/MWCNTs composite was successfully prepared by depositing silver nanoparticles on the surface by UV reduction.The synthesis conditions of Ag/MoO2/MWCNTs on the catalytic performance were systematically investigated.What is more,the oxygen reduction reaction(ORR)performance of Ag/MoO2/MWCNTs was investigated by cyclic voltammetry(CV)and linear sweep voltammetry(LSV),the stability of the product was investigated by the current-time(I-t)chronoamperometric response.The results showed that the optimal process parameters for preparing Ag/MoO2/MWCNTs were as follows:the reaction temperature of synthetic MoO2/MWCNTs was 160℃,the reaction time was 6 h,the mass ratio of MoO2(acac)2 to MWCNTs was 1∶1,the dosage of AgNO3 is 200μL each 1 mg MoO2/MWCNTs(20 mg·mL^-1).Ag/MoO2/MWCNTs showed ORR followed a four-electron pathway.This catalyst showed onset potential of 0.923 V,higher limiting current density of 6.34 mA·cm^-2 and the half-wave potential of 0.81 V.After 15000 s,the catalytic activity was still higher than 90.5%.