An effective bi-functional electrocatalyst for electrochemical water splitting using NiCo2O4 nanoparticles decorated with Polypyrrole nanocomposite

Abstract

The use of an efficient electrocatalyst to split water into H₂ and O₂ is crucial. Metal nanocomposites were combined with conducting polymers, specifically Polypyrrole, to provide materials for the electrodes used in the hydrogen evolution and oxygen evolution reactions (HER and OER). In this research, we used a hydrothermal technique to create a pure NiCo₂O₄@PPy nanocomposite. The grown samples were examined using several analytical methods. The XRD pattern of the synthesized products showed a crystalline NiCo₂O₄ Cubic phase. The vibrations of the metal–oxygen and pyrrole bonds were shown in the FTIR pattern. Using a NiCo₂O₄@PPy electrode in an alkaline medium for electrocatalysis demonstrates low overpotentials of 203 and 109 mV, correspondingly, for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER), at a benchmark current density of 10 mA cm⁻². The NiCo₂O₄@PPy nanocomposite shows increased electrocatalytic efficiency and reaction kinetics, as indicated by its short Tafel values of 46 mV dec^-1 for HER and 6–4 mVdec^-1 for OER. When related to NiCo₂O₄ and PPy alone, the TOF and electronic conductivity values of the NiCo₂O₄@PPy nanocomposite are significantly greater. Testing the nanocomposite stability over 50 h reveals minimal current loss, attesting to its exceptional stability; furthermore, it exhibits a high electrocatalytic active surface area of 1050 cm².