Electrodeposition of nickel oxyhydroxide nanoparticles on 2D MXene nanosheets: An efficient substrate for electrocatalytic oxidation of urea

In this study, nickel oxyhydroxide nanoparticles was controllably electrodeposited on the surface of MXene nanosheets modified pencil graphite electrode (PGE/MXene-NiOOH). The fabricated substrate was successfully utilized for electrocatalytic urea oxidation reaction (UOR) and hydrogen evaluation reaction (HER). The manufactured electrode was carefully characterized by field emission scanning electron microscopy, electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry techniques in detail. The PGE/MXene-NiOOH represents a large specific surface area making more active sites available which reduces UOR and HER overpotential and thereupon increases the kinetics of the reactions. The impedance results showed that the presence of MXene nanosheets improves the charge transfer rate. In the presence of urea, the oxidation wall was shifted 260 mV to less positive values at the current density of 10 mA cm−2 suggesting that hydrogen could be produced with less energy consumption via electrolysis of water in the presence of urea.