A vertically aligned flake like CuO/Co3O4 nanoparticle@g-C3N4 ternary nanocomposite: A heterojunction catalyst for efficient photo electrochemical water splitting

Abstract

Efficient utilization of solar energy for the conversion of water into hydrogen via photoelectrochemical (PEC) water splitting holds tremendous promise for sustainable energy production. In this study, we report a novel vertically aligned flake-like CuO/Co₃O₄ nanoparticle@g-C₃N₄ sheets ternary nanocomposite as a heterojunction catalyst for enhancing PEC water splitting efficiency. The ternary nanocomposite was synthesized via a facile and scalable method, resulting in a unique structure with vertically aligned CuO/Co₃O₄ nanoparticles in tight interface interaction with g-C₃N₄ sheets. The resulting heterojunction exhibited enhanced light absorption, efficient charge separation, and improved charge transfer kinetics, leading to significantly enhanced PEC water splitting performance. The as-synthesized ternary nanocomposite, such as CuO/Co₃O₄@g-C₃N₄ nanocomposite, demonstrated superior PEC activity with an enhanced photocurrent density, i.e., 0.88 mA/cm², which is higher than that of the pristine CuO (0.65 mA/cm²), Co₃O₄ (0.7 mA/cm²), and CuO-Co₃O₄ (0.77 mA/cm²) structures with linear sweep voltammetry under light irradiation. Additionally, the ternary nanocomposite exhibited excellent stability during 2 h PEC water splitting measurements under 1 h time interval chopped conditions. The remarkable performance of the vertically aligned CuO/Co₃O₄ nanoparticle@g-C₃N₄ ternary nanocomposite underscores its potential as a promising catalyst for efficient solar-driven hydrogen generation. This study not only provides insights into the design of advanced heterojunction catalysts but also contributes to the development of sustainable energy conversion technologies.