Enhancing the Electrochemical Performance of Bivo4 Nanoworm-Like Network Through Mn Doping: Effects of Mn Contents

Abstract

It is well-known that the electrochemical performance of materials largely depends on their specific surface area and pore characteristics. Therefore, several methods have been explored to increase their specific surface area of the materials. Among them, the reduction of particle size through doping or substitution was achieved. In this work, the Mn3+ ions were substituted into V5+ sites via a simple solution method. The results demonstrated that the addition of Mn provides a high specific surface area with mesopores size distribution. In addition, the specific surface area increases with increasing Mn content. For the electrochemical studies in an aqueous electrolyte, the enhanced electrochemical performances of BiVO4 can be attributed to the increase of active sites in smaller particles after Mn substitution. The BiV0.8Mn0.2O4 electrode exhibits the highest specific capacitance values of 223.4 F/g at a scan rate of 5 mV/s and 226.3 F/g at a current density of 2 A/g. In addition, the BiV0.8Mn0.2O4 electrode shows the highest energy density of 92.3 Wh/Kg at a current density of 2 A/g. Consequently, the substitution of Mn in BiVO4 can be regarded as a potential electroactive material for supercapacitor applications.

Keywords: Bismuth vanadate (BiVO4), Electrochemical properties, Materials characterization, X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS)