Amorphous MoS ₂ nanosheets grown on copper@nickel-phosphorous dendritic structures for hydrogen evolution reaction

In this study, we introduce highly active, efficient, and Pt-free electrodes (Cu@Ni-P@a-MoS ₂ ) fabricated on Ni foils, which have good conductivity and several a-MoS ₂ edge sites for the hydrogen evolution reaction (HER). A porous Cu dendritic structure on Ni foil was made by electro-plating utilizing hydrogen bubbles, and a Ni-P film that covered the dendritic structure was made by electro-less plating. Vertically grown a-MoS ₂ nanosheets were formed on the Cu@Ni-P dendritic structure by thermolysis. The structure has abundant active sites because of its particular structure, which was examined by SEM and TEM. XPS analysis was used to confirm that MoS ₂ was reduced completely, and the a-MoS ₂ nanosheet layer was characterized by Raman spectroscopy. Electrochemical experiments demonstrated that the electrode was highly effective for the HER with a low onset potential of 118.5 mV, and a current density of 10 and 100 mA/cm ² for 186 and 345 mV versus the reversible hydrogen electrode potential (vs RHE), respectively, a small Tafel slope of 60.5 mV/dec, and was stable after 2000 cycles. This study demonstrates that highly porous Cu@Ni-P@a-MoS ₂ electrodes, possessing a huge surface, are desirable for the HER and these findings will pave the way for a new form of highly efficient electrocatalysts.