Surface topography control of NiS/Ni3S4 nanosheets for the promotion of electrochemical performance

In this work, a two-step protocol was proposed to prepare NiS/Ni 3 S 4 composite nanosheets as an electrode material for supercapacitors. The composite nanosheets were prepared by hydrothermal sulfuration on the α-Ni(OH) 2 monolayer nanosheets that were produced by grinding the mixture of nickel salt and morpholine at room temperature. The results of morphology observation indicated that the composite prepared at 140 °C had sheet-like morphology and large lateral size. It presented high-specific capacitance (2070.0 F g −1 at current density of 2.5 A g −1 ) and excellent electrochemical stability (86% retention of initial capacitance after 10,000 charge–discharge cycles). It was considered that the high electrochemical performance of this composite could be attributed to its sheet-like morphology and the introduction of Ni 3 S 4 phase. A two-step protocol was proposed to prepare NiS/Ni 3 S 4 composite nanosheets as an electrode material for supercapacitors. In the first step, Ni(OH) 2 monolayer nanosheets were produced by grinding the mixture of nickel salt and morpholine at room temperature. In the second step, the Ni(OH) 2 monolayer nanosheets were sulfurated to NiS/Ni 3 S 4 composite nanosheets at hydrothermal conditions. Due to the well-defined sheet-like morphology, the nickel sulfide composite presented high electrochemical performance.