Three-dimensional nitrogen-doped graphene quantum dot/Ag leaf/Cu2O-Cu trunk/nickel foam nanocomposites as ultra-high-efficiency cathode electrocatalysts for hydrogen evolution reaction applications

Abstract

In this study, we developed a three-dimensional (3D) nitrogen-doped graphene quantum dot (NGQD)/Ag leaf/Cu₂O-Cu trunk/nickel foam (NF) structure as a high-performance electrocatalyst for hydrogen evolution reaction (HER) applications. This novel structure exhibited a high surface area, abundant electrochemically active sites, and efficient electronic transmission networks. In alkaline solution, the proposed structure demonstrated an overpotential of 112 mV at a current density of 10 mA/cm², along with a low Tafel slope of 28 mV dec⁻¹, indicating excellent HER activity. Furthermore, the structure exhibited stability over 100 h during durability testing. Overall, this innovative structure experimentally confirms that Cu-based materials can serve as efficient electrocatalysts for HER applications.