Dual Metal Sites Coengineered Graphitic Carbon Nitride as Green Electrocatalyst for Highly Selective Overall Water Splitting—A Sustainable Approach

Abstract

The development of efficient, low-cost, non-noble metal-oxide-based nanohybrid materials for overall water splitting is a critical strategy for enhancing clean energy use and addressing environmental issues. In this study, an interfacial engineering strategy for the development of bimetallic Co–Ni nanoparticles on graphitic carbon nitride (g-C₃N₄) using ultrasonication followed by coprecipitation is conveyed. These nanoparticles demonstrate high efficacy as bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline conditions. Co–Ni nanoparticles on graphitic carbon nitride demonstrate an increased surface area via ultrasonication and subsequent coprecipitation. The g-C₃N₄ combined with Co–Ni nanoparticles leads to the development of bifunctional catalysts that exhibit significant efficiency in both HER and OER, and their interfacial properties are investigated for the first time. The chemical composition and morphology of g-C₃N₄ integrated with Co–Ni nanoparticles significantly influence the modulation of redox-active sites and the facilitation of electron transfer, resulting in improved splitting efficiency. The interactions between the Co–Ni bimetal and g-C₃N₄ demonstrate exceptional electrochemical performance for water splitting. Consequently, the 20% 20–Co–Ni–graphitic carbon nitride electrode demonstrated superior HER performance, comparable to the other electrodes. In the results, it is indicated that an increased molar ratio of Co and Ni incorporated in graphitic carbon nitride significantly improves HER performance.