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采用两步易操作的水热法制备了还原氧化石墨烯(rGO)修饰泡沫镍(Ni foam)基体原位负载MnO_2纳米片(MnO_2/rGO@Ni foam)催化剂电极.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对电极的微观形貌和组成进行了表征.利用循环伏安法和计时电流法对电极对H_2O_2电还原反应的催化性能进行了系统的测试.根据测试结果得知,电极在3 mol/L Na OH和1 mol/L H_2O_2溶液中表现出最佳的催化性能.在该溶液中,当电位为-0.8V时,H_2O_2电还原反应的电流密度可以达到240 m A/cm2,高于同等条件下MnO_2直接生长在Ni foam上的电流密度180m A/cm2.通过不同温度下的极化曲线计算出了在该电极上H_2O_2电还原反应所需的活化能大小为21.53 k J/mol,明显低于文献中报道的数值.对比实验结果表明rGO的加入显著地改善了MnO_2催化剂的催化性能与稳定性.
The electrodes of MnO_2 / rGO @ Ni foam modified with rGO were prepared by a two-step hydrothermal method. X-ray diffraction (XRD) , Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the microstructure and composition of the electrode.The cyclic voltammetry and chronoamperometry were used to systematically test the catalytic performance of the electrode for the reduction of H_2O_2 According to the test results, the electrode showed the best catalytic performance in 3 mol / L NaOH and 1 mol / L H 2 O 2 solution, and the current of H 2 O 2 reduction reaction at -0.8 V The density can reach 240 m A / cm 2, which is higher than that of MnO 2 grown directly on Ni foam under the same conditions at a current density of 180 m A / cm 2 .Polarization curves at different temperatures are calculated for the H 2 O 2 reduction reaction The activation energy is 21.53 kJ / mol, which is obviously lower than the reported value in the literature.Comparison results show that the addition of rGO significantly improves the catalytic performance and stability of MnO 2 catalyst.