Engineering crystalline–amorphous interfaces in nickel oxide/porous carbon hybrids for enhanced electrocatalytic water splitting

Abstract

The strategic development of crystalline–amorphous interfaces has emerged as a promising approach to enhance catalytic activity in electrocatalytic water splitting by optimizing charge transfer kinetics and maximizing active site availability. In this work, we present an innovative methodology involving the precise engineering of crystalline–amorphous interfaces between nickel oxide (NiO) and porous carbon matrices, effectively combining the intrinsic catalytic properties of NiO with the superior electrical conductivity and defect-rich nature of carbon. The synthesized electrocatalyst delivers exceptional catalytic activity, achieving low overpotentials of 238 mV for HER and 335 mV for OER at-10 mA cm⁻² and 10 mA cm⁻² current density, while maintaining an outstanding overall water-splitting voltage of just 1.83 V. This rationally designed architecture addresses critical limitations of conventional NiO-based electrocatalysts, including insufficient active sites and suboptimal charge transfer efficiency, thereby providing a viable pathway for advancing efficient and sustainable water splitting technologies.