Electrodeposition of superhydrophilic and binder-free Mo-doped Ni–Fe nanosheets as cost-effective and efficient bifunctional electrocatalyst for overall water splitting

Design of electrodes that can simultaneously be excellent electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is important to produce hydrogen energy. In this study, Ni–Fe nanosheets were first created by electrochemical deposition method and then Mo-doped Ni–Fe nanosheets were created by hydrothermal electrode method. Then, electrode performance was investigated as electrocatalyst of HER and OER reactions. Morphology and microstructure of the electrodes were investigated using Field emission scanning electron microscopy (FESEM) and electrocatalytic activity was evaluated using LSV, Tafel test and EIS methods. The results of this study showed that among Ni–Fe electrodes sample, M-20 had the best electrocatalytic properties as well as molybdenum-doped electrode due to high surface area and also the synergistic effect of molybdenum doping showed better electrocatalytic behavior. In which, to generate a current density of 10 mA.cm−2 for the HER and OER, it required the 84 and 225 mV overpotentials, respectively. The electrode was also used as a bifunctional electrode for overall water splitting, which required a voltage of 1.81 V to generate a current density of 100 mA.cm−2. This study introduces an economical and effective method for the synthesis of electrocatalysts with appropriate activity.