Molecular architecture of PANI/V2O5/MnO2 composite designed for hydrogen evolution reaction

Abstract

An ever increasing demand for energy has mandated scientists towards exploring innovative and environmentally friendly energy production techniques that can meet the needs of human beings and the world at large. Among the various techniques, hydrogen evolution reaction (HER) is a cost-effective and efficient method that produces hydrogen, a better fuel, for meeting our energy requirements. The large surface area, good redox capacity, high electroactivity, and tunable bandgap of polyaniline (PANI) makes it a preferred candidate for various energy-related applications. Incorporating mixed metal oxides into a polymer enhances its catalytic activities and can be used as an electrocatalyst for HER. In situ chemical oxidative polymerization method has been carried out to synthesize PANI/V2O5/MnO2 composite. The characterization studies of PANI/V2O5/MnO2 composite are done using XRD, FT-IR, BET, XPS, and FE-SEM analysis. The PANI/V2O5/MnO2 composite is used for linear sweep voltammetry studies and shows that it acts as an efficient electrocatalyst which gives an overpotential of 130 mV at 10 mA/cm2. The high electrocatalytic activity of the composite is due to the better surface phenomenon that is enhanced by the high porosity and surface area. The electrochemical impedance spectroscopy also shows lower charge transfer resistance for the PANI/V2O5/MnO2, confirming its excellent electroactivity. 90% of the current density is retained even after 7200 seconds, validating its stability.