Facile synthesis of Co₃Te₄-Fe₃C for efficient overall water-splitting in an alkaline medium

The large amounts of attention directed towards the commercialization of renewable energy systems have motivated extensive research to develop non-precious-metal-based catalysts for promoting the electrochemical production of H₂ and O₂ from water. Here, we report promising technology, i.e., electrochemical water splitting for OER and HER. This work used a simple hydrothermal method to synthesize a novel Co₃Te₄-Fe₃C nanocomposite directly on a stainless-steel substrate. Various physical techniques like XRD, FESEM/EDX, and XPS have been used to characterize the good composite growth and confirm the correlation between the structural features. It has been shown that the composite's morphology consists of interconnected particles, each uniformly coated with a thin layer of carbon. This structure then forms a porous network with defects, which helps stabilize the material and improve its charge conductivity. XPS analysis shows that combining Fe₃C with Co₃Te₄ adjusts the atomic structure of both metals. This interaction creates redox sites (Fe³⁺/Fe²⁺ and Co³⁺/Co²⁺) at the Co₃Te₄-Fe₃C interface, which are crucial for activating redox reactions and enhancing electrochemical performance. The results also confirm the presence of multiple synergistic active sites, which contribute to improved catalytic activity. The optimized chemical composition and conductive structure result in enhanced electrocatalytic activity of Co₃Te₄-Fe₃C towards electron transportation between the material interface and medium. It is found that the Co₃Te₄-Fe₃C catalyst exhibits robust OER/HER activity with reduced overpotential values of 235/210 mV@10 mA cm^-2 and Tafel slopes of 62/45 mV dec^-1 in an alkaline solution. For overall water-splitting, cell voltages of 1.44, 1.88, and 2.0 V at current densities of 10, 50, and 100 mA cm^-2 were achieved with a stability of 102 h. The electrochemically active surface area of the composite is 1125 cm², indicating that a large surface area offered numerous reactive sites for electron transfer in the promotion of the electrochemical activity. The enhancement in catalytic performance was also checked using chronoamperometry analysis, reflecting long-term stability. Our results provide a novel idea for designing a composite of carbide with chalcogenide with robust catalytic mechanisms, which is useful for various applications in environmental and energy conversion fields.