Study on the preparation of composite MnO2

Abstract

The manganese dioxide (MnO2) is a material that has broad application prospects and economic value, which is used in various fields. However, the poor conductivity, less active sites and the easy collapse of the structure during the reaction, limit application. In this paper, three kinds of MnO2 were prepared by simple method, α-MnO2, β-MnO2, and γ-MnO2. And the properties of the sample were further analyzed by Brunauer-Emmett-Teller (BET), X-ray diffffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX) and fourier transform infrared spectroscopy (FTIR). Then α-MnO2 was chosen as the precursor of this study. Three different ratios of transition metal Ni and Co are respectively loaded with α-MnO2. Electrodes made of 7 different samples including α-MnO2, complete cyclic voltammetry test. Results show that: (1) α-MnO2 is not easy to collapse and suitable for precursor; (2)the addition of metal Ni and Co increases the specific surface area of the material to varying degrees. Co@a-MnO2-2 has the highest specific surface area and porosity, which can provide more active sites when applied; (3)all seven samples have good capacitance characteristics. The best is Co@a-MnO2-0.5, but Co@a-MnO2-2 is very close to Co@a-MnO2-0.5. Comprehensive analysis, the best ratio for this study is Co@a-MnO2-2.