Exploring Synergistic Effects of CoCHCN Electrocatalyst to Accelerate Oxygen Evolution Reaction for Sustainable Green Hydrogen production

A polyaniline-coupled cobalt carbonate hydroxide (CoCHCN) electrocatalyst was rationally designed to regulate interfacial charge transport and accelerate the oxygen evolution reaction (OER) kinetics. Structural, morphological, and spectroscopic analyses confirm the uniform coating and strong electronic interaction between polyaniline (CN) and cobalt carbonate hydroxide (CoCH), generating abundant accessible active sites and improved electrical conductivity. In 1 M KOH, CoCHCN achieves a low overpotential of 282 mV at 10 mA cm⁻² and a small Tafel slope of 48 mV dec⁻¹, reflecting rapid reaction kinetics and favorable reaction pathways. The catalyst exhibits outstanding operational stability for 120 h with negligible potential decay, low charge transfer resistance (3.8 Ω), and a high electrochemically active surface area, enabling efficient electron transfer. Arrhenius analysis reveals a reduced activation energy after CN coupling, confirming kinetically promoted OER processes. Furthermore, an alkaline and solar-driven electrolyzer assembled with a CoCHCN anode delivers 10 mA cm⁻² at 1.58 V, demonstrating practical applicability. This work highlights that conductive polymer coupling is an effective strategy to enhance electron-ion transport and improve scalable water oxidation performance.