Chromium and vanadium incorporation in NiS-MoP nanocomposite for enhanced overall water-splitting materials

Developing highly efficient, cost-effective, and earth-abundant catalysts is a critical challenge in advancing water splitting technologies. The development of effective electrocatalysts for overall water splitting has garnered considerable scientific attention. In this study, we report the synthesis of a novel nanocomposite comprising vanadium-doped molybdenum phosphide (MoVP) and chromium-doped nickel sulfide (NiCrS) via a simple and economical hydrothermal method. The novelty of this work lies in the strategic combination of transition metal-doped phosphide and sulfide materials to exploit synergistic interactions, thereby enhancing electrocatalytic performance. Comprehensive characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) confirmed the formation of well-defined crystal structures, distinct nanostructured morphologies, and high material purity. The synthesized MoVP–NiCrS nanocomposite demonstrated significantly reduced overpotential and Tafel slope values in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) experiments, indicating superior electrocatalytic activity. Specifically, the nanocomposite exhibited an overpotential of 137.6 mV and a Tafel slope of 33.17 mV/dec for HER, while for OER, the values were 120.4 mV and 46.96 mV/dec, respectively. Cyclic voltammetry (CV) analysis revealed that the composite materials displayed enhanced cathodic and anodic activities compared to their pristine counterparts. Additionally, electrochemical impedance spectroscopy (EIS) was employed to assess the conductive properties of the electrocatalysts. Nyquist plots showed that the MoVP–NiCrS nanocomposite possessed a relatively low charge-transfer resistance (Rct) and high electrical conductivity. © 2025 Elsevier B.V., All rights reserved.