Synthesis of Ni3S2 with various sulphur sources and their HER and OER performance

It is highly anticipated to produce hydrogen via water splitting, which can be electrocatalyzed by nonprecious electrocatalysts. Nickel sulfide (Ni3S2) has attracted considerable attentions due to its high electrochemical performance for hydrogen evolution reaction and oxygen evolution reaction. In this study, nano-sized Ni3S2 binder-free electrodes are directly grown on Ni foam via various method. The obtained results show that interconnected sheet-like Ni3S2 with a hydrophilic surface, which was prepared from Na2S via hydrothermal method, exhibited best HER and OER electrocatalytic performance. The thin nanosheets structure could offer more active center of HER and OER in aqueous alkaline electrolyte and its hydrophilic surface could also facilitate the ions transfer on the interface of electrode and electrolyte. The best Ni3S2 electrode made from Na2S showed overpotential of 43 mV and 127 mV at the current density of 10 mA cm-2 and 100 mA cm-2 respectively. For OER, it also shows superior electrochemical activity and durability.