Ni-P codoping engineered MoS₂ basal planes for electrocatalytic water splitting: insights from density functional theory

The development of efficient bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting is crucial for clean energy generation. This study investigated the potential of substitutional heteroatom doping in metallic 1T-phase MoS₂ monolayers (MLs) using first-principles calculations. Ni and P codoping significantly improved the electrical conductivity and active site reactivity of the distorted 1T-MoS₂ lattice. Doping modulated the electronic band structure, inducing spin-polarized states with enhanced d-band conductivity near the Fermi level. This manipulation, governed by the altered valence and conduction bands, also facilitated efficient charge transfer and reduced interfacial resistance. Furthermore, the strong dopant promoted the adsorption behavior at various active sites on the surface, lowering the Gibbs free energy for the HER (0.083 eV) and decreasing the OER overpotential (0.39 V). Therefore, the heteroatom doping of 1T-MoS₂ MLs is a powerful strategy for developing advanced and low-cost electrocatalysts that can accelerate water splitting and operate without platinum.