Green and sol–gel synthesis of perovskite type LaCo0.2Mn0.8O3 nanoceramics as potential materials for electrochemical hydrogen storage: A comparative study

Abstract

The high consumption of fossil fuels has contributed significantly to environmental pollution and climate change. One strategy to address these challenges is utilizing renewable energy sources, such as hydrogen. This research marks the first attempt to synthesize perovskite-type LaCo0.2Mn0.8O3 nanoceramics using green and sol–gel methods and to evaluate their performance as potential materials for electrochemical hydrogen storage applications. The orthorhombic structure of the samples was identified from XRD patterns. The average crystallite size of LaCo0.2Mn0.8O3 nanoceramics prepared using green and sol–gel methods was calculated using the Debye–Scherrer equation and found to be 31 and 23 nm, respectively. The morphological studies confirmed the nanoscale formation of LaCo0.2Mn0.8O3 nanoceramics with an approximately spherical shape in both methods. The BET analysis revealed that the samples showed a type II isotherm. The electrochemical properties of the samples studies using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge chronopotentiometry (CP) techniques. The specific capacitance value of LaCo0.2Mn0.8O3 nanoceramics synthesized using the sol–gel (1164F/g) method is higher than the green (564F/g) method, which indicates its superior energy storage capability. Additionally, the discharge capacity of LaCo0.2Mn0.8O3 nanoceramics prepared using the sol–gel method (1008 mAh/g) is significantly higher than that of the green method (387 mAh/g) in 3 M KOH electrolyte solution.