Enhanced electrocatalytic activity with an incorporation of oxygen on the surface of di-nickel di-selenide for water splitting: A DFT-based computational design

Herein, we present a density functional theory study investigating the influence of oxygen on the surface of metal and metal chalcogenides (O–Ni₂Se₂) with respect to their trifunctional behavior. Our results show that the incorporation of oxygen into Ni₂Se₂ enhances the electrical conductivity of the electrochemical reactions. In particular, the involvement of the transition metal (Ni) and metal chalcogenide (Se) results in nearly zero Gibbs free energy of hydrogen adsorption for the HER and a lower overpotential for the OER/ORR activity in the presence of oxygen at different active sites of the catalyst. Furthermore, all atoms involved in this study (O–Ni₂Se₂) are strongly bonded together and constrained by the binding energy towards the intermediates. This binding energy originates from the electron-donating ability around the d-band center of the catalyst, as confirmed by the partial density of states around the Fermi level. This work is expected to create a new pathway for the development of cost-effective trifunctional catalysts.