Enhancement of electrochemical performance of hydrothermally synthesized CoNiO2/PANI for OER efficiency
Zarghuna Firdous, Samira Elaissi, Tahani Rahil Aldhafeeri, Syed Kashif Ali, Abhinav Kumar
Abstract
The designing of effective, easily available and eco-friendly electrocatalysts for hydrogen production is crucial for minimizing energy utilization in electrochemical water splitting. Also for commercialization, earth-abundant catalysts and synthesizing cost-efficient materials with exceptional properties are in critical demand. For this purpose, we report the synthesis of CoNiO 2 /PANI nanocomposite employing hydrothermal method for OER in alkaline medium (1 M KOH). The synthesized electrocatalyst CoNiO 2 /PANI has been analyzed through various physical characterization techniques, involving X-ray diffraction (XRD), scanning electron microscopy (SEM) as well as electrochemical studies, to assess its crystallinity , morphology and electrochemical efficiency for OER . The as-prepared nanohybrid material had reduced overpotential (η) of 229 mV, with Tafel gradient of 37 mV/dec at 10 mA/cm 2 . CoNiO 2 /PANI nanohybrid displays an improved electrochemical surface area (ECSA = 316.25 cm 2 ). EIS investigations indicated that charge transfer kinetics at catalyst-electrolyte interface could be feasible, with smaller R ct reading (0.08 Ω) leading to boost in electrochemical performance . Chronopotentiometry (CA) showed greater stability over 50 h following 3000 th stability cycles. All these findings indicate that composite of PANI with CoNiO 2 enhances ion transport and efficient electron conduction at electrode/electrolyte interface. The outcomes of this study reveal a novel, stable and effective catalyst that could potentially be used in the development of electrocatalytic hydrogen generation technologies.