Theoretical and experimental study of flower-like NiMoS/NiO/NF with interface layer as a novel highly efficient bifunctional-electrode toward supercapacitor and HER

Electrocatalytic water splitting and supercapacitor systems are considered one of the most imperative sustainable energy storage and conversion technologies as an alternative clean energy carrier/source to fossil fuels in order to address the pressing global warming problems. For achieving sustainable electrochemistry devices, highly efficient and superior durability electrocatalysts must be prepared through a facile and controllable approach. This study successfully demonstrated the development of a binder-free 3D- flower-like amorphous structure composite with self-assembled nanosheets supported on Nickel foam (NiMoS/NiO/NF) by a simple two-step hydrothermal technique as advanced electrocatalysts for alkaline hydrogen evolution reaction (HER) and supercapacitor. The as-obtained NiMoS/NiO/NF only needs a overpotential of 43 mV vs. RHE to reach 10 mA.cm−2 and remained stable after long-term HER tests. In the following, the nanostructure was operated as an electrode in the supercapacitor. According to the Galvanostatic Charge-Discharge (GCD) teats, the specific capacitance of NiMoS/NiO/NF was measured as 999F/g. Such outstanding NiMoS/NiO/NF performance can be ascribed to the synthesis of the interface layer (NiO), which makes the robust adhesion between NF and the final layer (NiMoS). The amorphous morphology with multi-component doping and heterojunctions, optimizes the hydrogen desorption sites, which leads to significant HER catalytic activity. The present experimental results and density functional theory (DFT) study offer a cost-effective, and convenient pathway to produce highly efficient non-nobel-based metal as high-valued multifunctional materials.