In situ growth of CaMoO4 on electropolymerized PANI as a hybrid electrocatalyst for enhanced oxygen evolution

Abstract

Electrochemical water splitting stands as a promising avenue for sustainable hydrogen production, with the oxygen evolution reaction (OER) playing a pivotal role. Efficient and durable electrocatalysts are crucial for expediting the sluggish kinetics of OER. In this work, we investigate the synthesis and performance of a novel CaMoO₄/polyaniline (CaMoO₄/PANI) composite catalyst for OER. In situ growth of CaMoO₄ has been done after the electropolymerization of polyaniline on nickel foam (NF), offering advantages such as improved structural integrity, increased surface area, and enhanced electroconductivity. Electrochemical characterization reveals that CaMoO₄/PANI exhibits superior catalytic activity, with an overpotential of 233 mV at 10 mA cm⁻², outperforming pristine CaMoO₄, PANI, and certain current similar non-noble-metal electrocatalysts. Electrochemical studies reveal that the exceptional activity can be attributed to reduced charge transfer resistance, underscoring the catalyst's enhanced efficiency. Furthermore, multistep chronopotentiometry confirms excellent robustness of the catalyst electrode as well as its excellent mass transportation. This work highlights the potential of inorganic oxide/conductive polymer composites as efficient catalysts for OER, offering insights for future developments in sustainable energy technologies.