Fabrication of MnO2-V2C nanocomposite as an efficient electrode material for water splitting Application

Abstract

It is observed over the past few decades, environmental problems and energy shortage problems are major issues because of the consumption of fossil fuels. So, to overcome these issues some serious efforts are needed in order to develop renewable energy resources for sustainable development of economy and energy production. Electrocatalytic water splitting is environment friendly technique for production of hydrogen(H2) and Oxygen (O2). Herein we study the novel and emerging class of 2D materials named as MXenes and its nanocomposite formed with MnO2.Here Synthesis of V2C@MnO2 nanocomposite by liquid phase precipitation method with improved electrocatalytic activity and stability for water splitting is reported. Vanadium carbide MXene acts as a conductive material to provide rapid electron transfer. The properties of V2C@MnO2 nanocomposite exhibits improved hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance at a low onset potential. Synthesized nanocomposite of V2C@MnO2 exhibits improved performance at low over potential of 19.7 mV at current density of 10mAcm-2 while for V2CTx it was 139 mV. Similarly, the nanocomposite shows good OER activity at low over potential 570 mV at 10 mAcm-2 while for MXene it was 600 mV with a long term stability of 16 hours. Tafel slopes for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) shows that kinetics of MXene was slow as compared to MnO2@V2C nanocomposite. Tafel slope of HER for MXene(V2CTx) was 96mV/dec and for nanocomposite it was 90 mV/dec . Similarly, for oxygen evolution reaction (OER) Tafel slope for V2CTx was 224 mV/dec and for nanocomposite it was 131 mV/dec. Also nanocomposite shows low charge transfer resistance of 99 ohms and for V2CTx it was 220 ohms. Above results shows that MnO2@V2C nanocomposite shows best OER, HER activity. The structural as well as morphological properties of the compounds were investigated using XRay diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersion spectroscopy (EDS), confirming the successful formation of nanocomposite while retaining the twodimensional (2D) structure of MXene. To analyse the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity Linear sweep voltammetry was performed.