Self-assembled flower-like ZnCo₂O₄hierarchical superstructures for high capacity supercapacitors

Abstract

Self-assembled ZnCo2O4 nanosheets were synthesised by one-step hydrothermal method and its electrochemical supercapacitor properties were investigated in 2M aqueous KOH solution. Interesting capacitive properties were observed with superb cyclic stability even at a current density of 20 A/g. Specific capacitance value of 1691 F/g was obtained at a current density of 3.75 A/g with an energy density of ~57.4 Wh/Kg. The experimental findings provide useful insights in the design of supercapacitors for potential high performance energy storage application in future.

Synthesis of Zn0.3Co2.7O4 porous willow-leaf like structure for enhanced electrocatalytic oxygen evolution reaction

“…with different nano-structured morphologies and sizes have been reported [5,6], to the best of our (II) substituted by Zn (II) ions. Therefore, the partially substituted Zn x Co 3-x O 4 with other different compositions are also high anticipated substitutions with great potential for electrochemical energy storage, but such reports are still limited [7,8].…”

Pulse-duration dependence of saturable and reverse saturable absorption in ZnCo2O4 microflowers

“…Interestingly, 2D structures can further be aggregated physico-chemically to form a stable morphology of 3D materials. For example, spinel structures of ZnCo2O4 (ZCO) microflowers are formed by the growth and aggregation of several 2D nanosheets [13,14]. Among the series of Zn-based spinel, e.g.…”

“…Apart from the unique spinel structures, ZCO has large electrical conductivity and high optical transmission over broadband wavelength regime and therefore well-known as transparent conducting oxides (TCOs) in optoelectronic device [22,23]. ZCO nanostructures with flower-like features are of particular important because thin edges and sharp tips associated with such geometry, provides favourable enhancement of the optical field [13,14,24]. Despite having high linear optical transmission in UV-Vis-NIR regime with the advantage of wide bandgap, the nonlinear optical response of ZCO microstructures are hitherto unexplored.…”

“…We synthesized ZCO microflowers by using low cost, low temperature hydrothermal route and the details can be found elsewhere [13,14]. Precisely, under hydrothermal conditions, supersaturation takes place between the co-precipitated particles, e.g.…”

“…The SEM images of the synthesized ZCO microflowers are shown in Fig. 1 The strongest of the Raman band at 673 cm -1 is arising from the relative contribution of two peaks at 658 and 682 cm -1 , both having A1g symmetry [13,14]. To determine the bandgap, we showed in Fig.…”