Electronic Structure Tuning of CoS₂ via N-Heteroatom Doping for Efficient Oxygen Evolution Reaction Application

A crucial aspect for developing the catalyst is to overcome the oxygen evolution reaction (OER) bottleneck, which can be achieved through forming conductive network for efficient charge transport across the cocatalyst structure using N-heteroatoms doping and simultaneously accelerating the active catalyst centres. As the nitrogen have the ability to modulated the electronic structure of the host material, owing to its promising electron-withdrawing ability from the neighboring metal-catalyst via donor–acceptor interaction, which results in the optimal electronic structure of the cocatalyst with improved material conductivity and catalytically active sites. In this study, we synthesized cost-effective nitrogen-doped CoS₂ (N,CoS₂) aggregated nanospheres using a hydrothermal method followed by N-atom doping to enhance catalytic active sites and redox kinetics for efficient OER application. The proposed N,CoS₂ exhibits significantly lower overpotential (271 mV) and Tafel slope (63 mV dec⁻¹) along with the improved Faradaic efficiency compared to pristine CoS₂ (294 and 99 mV dec⁻¹), indicating that heteroatom doping enhances OER kinetics. Furthermore, N-CoS₂ demonstrated excellent robustness under varied current rates and showed outstanding durability, with long-term stability (75 h) at steady 10, 100, and 500 mA cm⁻² current densities.