Unleashing the potential of bifunctional electrocatalyst: Designing efficient Ni@MnS/SGCN nanocomposite for clean energy conversion

The two main problems facing the world now are global warming and fossil fuel depletion. Using hydrogen as a substitute energy source is one way to potentially solve these issues. A sustainable, renewable, and environmentally beneficial energy source is electrochemical water splitting among the various energy routes available. The difficult problem is to create a strong, affordable, and effective dual-purpose electrocatalyst that increases electrochemical water splitting. Because of their strong and excellent electrical conductivity, transition metal sulfides are utilized in electrochemical energy storage systems. MnS is employed as the electrocatalyst in this work initially, and its electrocatalytic properties are then increased by two methods: doping and synthesis of composite material. The facile and simple co-precipitation method is employed to create a series of Ni-doped MnS with different percentages of the weight of Nickel (10 %, 8 %, 6 %, 4 %, and 2 wt %) and 6 % Ni@MnS composite material with varied weight percentages of SGCN (10, 30, 50, 70, and 90 % wt. %). The electrocatalyst is characterized using XRD, SEM and EDX to examine its composition, size, and structure. Electro-catalysts are employed as working electrodes and are placed using the drop-casting method on the FTO glass. Doping and the production of composite materials increase the activity of electrochemical water splitting, as demonstrated by EIS, CV, LSV, and chronopotentiometry. 70 % Ni@MnS/SGCN produces the optimum electrochemical water splitting activity when used with a lower overpotential of 380 mV for oxygen evolution reaction (OER) and 650 mV for hydrogen evolution reaction (HER) to attain 10 mA/cm² current density. The results thus indicate that 70 % composite material could potentially have been employed as an electrocatalyst in the process of water splitting.