Improved catalytic performance of (Fe, Cr)-ZnO/g-C3N4 nanocomposite towards electrocatalytic water splitting for clean energy

Abstract

The declining quantity of nonrenewable energy sources and rising in temperatures globally pose serious concerns. Therefore, electrochemical water splitting emerges as a highly efficient and cost-effective method of preparing hydrogen and oxygen, utilizing materials such as metals and their oxides. Beyond precious metals, carbon-based materials have been realized to be efficient in facilitating these reactions. To improve efficiency and optimize potential applications, it has also been established that incorporating metal oxides into the layers of the graphite can significantly improve the activity of HER and OER. In this study, we introduce a newly designed composite electrocatalyst, (Fe, Cr)-ZnO/g-C₃N₄ ((Fe, Cr)-GZN), which demonstrates enhanced electrocatalytic performance. The composite material was synthesized through the coprecipitation of (Fe, Cr)-ZnO with g-C₃N₄. The electrocatalyst's structure was fully analyzed using the important characterization techniques. FTO glass was employed to electrodeposit catalysts to facilitate water splitting investigations. The (Fe, Cr)-GZN composite demonstrated excellent electrochemical water splitting performance, with low overpotentials of 304 mV and a Tafel slope of 89 mV dec⁻¹ for OER, resulting in 10 mA cm⁻² (current density). This performance outperforms Cr-GZN and Fe-GZN composites, demonstrating the (Fe, Cr)-GZN composite's potential as an extremely efficient electrocatalyst for water splitting.