Breaking barriers in electrocatalysis: unleashing the power of highly efficient Mn/CoS@S-g-C₃N₄ nanocomposite for electrocatalytic water splitting and superior H₂ production

The growing need for sustainable energy has led to a great deal of interest in creating effective and reasonably priced non-precious electrocatalysts as substitutes for precious metal-based electrocatalysts, which are expensive and frequently show poor long-term stability under extreme reaction conditions, making them less useful for sustainable energy solutions. In this study, we introduce Mn/CoS@S-g-C₃N₄, a novel electrocatalyst composed of manganese-doped cobalt sulfide integrated with sulfur-doped graphitic carbon nitride (S-g-C₃N₄), synthesized through a simple co-precipitation method. The synergy between Mn and CoS within this composite provides an optimized electronic structure, enhancing the transfer of electrons and presence of S-g-C₃N₄ serves as both a stabilizing matrix and a conductive support, exposing more active sites which enhances both performance and durability. This Mn/CoS@S-g-C₃N₄ catalyst demonstrated low overpotentials of 306 mV for OER and 404 mV for HER at a current density of 10 mA/cm² in 1 M KOH solution, alongside favourable Tafel slopes of 63.72 mV/dec for OER and 73.22 mV/dec for HER. Additionally, the use of earth-abundant and low-cost elements (Mn and Co) makes Mn/CoS@S-g-C₃N₄ a highly economical choice, addressing both performance and cost-effectiveness in water splitting applications.