Experimental and Computational Analysis of Vanadium Carbide MXene and MnO2-V2C Nanocomposite with Enhanced Energy Storage Ability

Abstract

Over the last several decades, Energy storage systems has taken the world’s attraction towards itself and thus human beings have made a lot of development in terms of efficient and highperformance technologies which is the outcome of continuous and endless research contribution of scientists. Herein we study the novel and emerging class of 2D materials named as MXenes and its nanocomposite formed with MnO2. The research however on MXenes for supercapacitor applications has focused primarily on Ti3C2 despite of the fact that there are 20+ members of the large family of MXene materials which can be accounted for energy storage applications. So, the studies on various MXenes are emerging with inevitable results which are already achieved by Mo2C, Nb2C and Ti2C in aqueous electrolytes. Though many other MXenes exist which are to be explored for aqueous supercapacitor applications. This work entails detailed experimental as well as computational study of V2C and MnO2-V2C nanocomposite highly capable for supercapacitor applications, so we report electrochemical behavior of vanadium carbide MXene and MnO2-V2C nanocomposite with varying percentages of MnO2 in the nanocomposite. Excellent specific capacitance of 551.8F/g was achieved for MnO2-V2C nanocomposite in 1M KOH electrolyte solution which is twice times higher than the gravimetric capacitance obtained for V2C that is 205F/g and reported values of V2C. Wet etching method for the preparation of Pristine MXene and Co-precipitation method was initiated to synthesize MnO2-V2C nanocomposite. The structural as well as morphological properties of the compounds were investigated using X-Ray diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersion spectroscopy (EDS), confirming the successful formation of nanocomposite while retaining the two-dimensional (2D) structure of MXene. The computational study was also conducted using Density Functional Theory (DFT) for analyzing the increased in density of states DOS, its band gap structure and its enhanced electronic conductivity.