Graphdiyne-supported nickel nanoparticles for enhanced electrocatalytic water oxidation performance

Abstract

The substitution of precious metals, such as ruthenium and iridium, to boost the performance of the electrocatalytic water oxidation reaction (OER) is of paramount importance in energy science and technology. However, despite recent advances, the development of nonprecious metals for the OER is still hindered by their high overpotentials, sluggish kinetics, and inadequate stability. Optimization of the electronic structure of non-precious transition metal nanomaterials plays a crucial role in enhancing their performance in the electrocatalytic OER. In this study, we employed a facile reduction method for the in situ loading of nickel nanoparticles onto graphdiyne (GDY) and obtained the Ni NPs/GDY catalyst. Due to the distinctive chemical and physical properties of GDY, its combination with nickel nanoparticles results in strong electronic interactions, effectively modulating the electronic and geometric structures of the Ni NPs/GDY catalyst and significantly improving its electrocatalytic performance in the OER. The Ni NPs/GDY catalyst exhibited a low overpotential of 294 mV at a current density of 10 mA cm⁻² and a small Tafel slope of 56.8 mV dec⁻¹ in 1 M KOH, along with excellent electrocatalytic kinetic properties and an ultra-long electrocatalytic stability of approximately 90 h. Compared to the reference catalysts Ni NPs and GDY, the Ni NPs/GDY catalyst demonstrated superior performance, which is primarily attributed to the electronic interactions generated upon the loading of nickel nanoparticles to GDY, which can expose more catalytic sites, facilitate charge transfer, and simultaneously prevent catalyst aggregation during the catalytic process. The findings of this work can provide new insights for exploring more efficient electrocatalysts for the OER.