Ni3S2 coated ZnO array for high-performance supercapacitors

One-pot synthesis of hierarchically nanostructured Ni3S2 dendrites as active materials for supercapacitors

“…Likewise, dendrites can hardly be formed at low reaction temperature of 90 C. Consequently, it is believed that the optimum growth temperature of Ni 3 S 2 dendrites is 120 C. Figure 4(a) shows the cyclic voltammetry (CV) analysis at various scan rates from 2 mVs À1 to 30 mVs À1 . Clearly, a couple of redox peaks are observed within the potential range of 0-0.6 V, which is consistent with that reported previously in the literatures, mainly attributed to the Faradaic redox reaction between Ni 2+ /Ni 3+ and OH À in alkaline electrolyte, as shown below: [35,37] Ni 3 S 2 + 3OH À $ Ni 3 S 2 (OH) 3 + 3e À Notably, the characteristic CV shapes for Ni 3 S 2 dendrites prepared at 120 C almost do not show any changes along with increasing potential scan rates, implying its desirable fast charge/ discharge properties, which is generally required by power devices. As can be seen, with the increase of scan rate, the anodic peaks shift evidently towards positive potential and the cathodic peaks shift towards negative potential, respectively, which is caused by the strengthened electric polarization generated during the charge-discharge process.…”

“…Clearly, except for three relatively strong peaks centered at 2u = 44.5 , 51. [35,37] To gain insight into the nanostructure of as-prepared Ni 3 S 2 3D hierarchical dendrites, TEM and HRTEM measurements were carried out. The detailed characteristic of an individual dendrite with multiple branches is shown in Fig.…”

“…[29] Among numerous pseudocapacitive materials used as electrode for supercapacitors, Ni 3 S 2 , presenting various morphologies and nanostructures, has become the most investigated one recently, because of its low cost, high specific capacitance and easy synthesis. [30][31][32][33][34] [37] as well as the environmentally friendly hydrothermal synthesis of nickel sulfide nanospheres. [38] Therefore, if 3D hierarchical nanosturtures were designed successfully and applied as supercapacitor electrode, it would exhibit a considerable increase of the active material availability for electrochemical performance.…”

Ag3O4grafted NiO nanosheets for high performance supercapacitors

“…It is worth mentioning that the cyclic stability of Ag 3 O 4 grafted NiO (5 wt. % of Ag) is better than that of other reported results[45][46][47] . The flower like structure may provide easiest intercalation/deintercalation paths for ions without much change in the structure for prolonged cycles and results in higher cyclic stability.To elucidate the electrical conductivity and ion transfer ability of the electrodes, electrochemical impedance analysis was made.Fig.…”

Mechanical alloying synthesis of Ni 3 S 2 nanoparticles as electrode material for pseudocapacitor with excellent performances

“…A variety of methods have been reported to synthesis nickel sulfide. For instance, Cho et al [19] reported the Nano Ni particle embedded Ni 3 S 2 powders prepared by means of melt spinning, Zhang et al [28] presented the synthesis of Ni 3 S 2 by one-pot hydrothermal route, Zhou et al [29] presented the growth of Ni 3 S 2 nanorod on nickel foam, and Xing et al [30] recently demonstrated the fabrication of Ni 3 S 2 nanotube array on ZnO, all these electrode materials exhibited excellent electrochemical performances, however, these methods either need a long preparation period or expensive cost, so it is the time to adopt new method to prepare Ni 3 S 2 nano-material. In our opinion, one of the most promising methods to prepare nanocrystalline material is the mechanical alloying of solids under inert atmosphere.…”