Benchmark-Level Oxygen Evolution Catalysis via Synergistic Coupling of FeCo ₂ S ₄ and MXene in a Sustainable Hybrid Electrocatalyst

Over the past few years, atomically thin materials have drawn considerable interest as robust materials for water-splitting catalysis, as they possess a unique two-dimensional architecture that offers considerably exposed active catalytic binding sites and favorable charge transfer pathways for hydrogen generation. The latter is achieved by effectively driving the hydrogen evolution reaction (HER) and the comparatively slower counter reaction, the oxygen evolution reaction (OER). The sluggish kinetics of the OER has driven intensified efforts to engineer durable, high-activity electrocatalysts capable of operating synergistically with HER to achieve efficient and balanced hydrogen production. This paper reports a hybrid electrocatalyst with a nanostratified morphology, consisting of layered MXene (Ti3C2Tx) sheets decorated with FeCo2S4 (FCS) nanoclusters. The MXene serves two distinct functions as a support for maintaining the structural integrity of FCS and promotes the formation of high-density catalytic interfaces. The structural analysis reveals the heterostructure composed of the desired integration of FCS and MX components, while the electrochemical analysis reveals a good density of catalytically active centers. Benefiting from these excellent attributes, the catalyst exhibits enhanced charge transport kinetics for the targeted OER process. The OER overpotential of 143 mV is observed for reaching the standard current density of 10 mA cm–2. This performance is corroborated by Tafel analysis with a slope of 51 mV dec–1 in the 1 M KOH electrolytic medium. The excellent electrocatalytic performance of FCS/MX is also substantiated by excellent long-term stability. The observed electrochemical performance in terms of overpotentials reported here is among the best achieved thus far and portrays MXene hybrid systems as efficient and cost-effective OER catalysts.