In the present work, flower-like mesoporous MoS2 has been synthesized via a one step hydrothermal approach. The electrochemical performance of synthesized flower-like MoS2 nanostructures for supercapacitor applications has been probed via cyclic voltammetry, galvanostatic charging-discharging and electrochemical impedance spectroscopy in 1 M H2SO4 (acidic electrolyte), 1 M Na2SO4 (neutral electrolyte) and 2 M KOH (basic electrolyte) electrolytes using a three electrodes configuration. On the basis of electrochemical measurements, it has been observed that as-prepared flower-like MoS2 exhibits specific capacitances of 225 F g−1, 205 F g−1 and 123 F g−1 in 1 M H2SO4, 1 M Na2SO4 and 2 M KOH electrolytes at 1 A g−1, respectively. Moreover, for the MoS2 electrode the diffusion coefficients in 1 M H2SO4, 1 M Na2SO4 and 2 M KOH electrolytes are found to be 8.52 × 10−10 cm2 s−1, 5.41 × 10−10 cm2 s−1 and 8.35 × 10−10 cm2 s−1, respectively. Further, the relaxation time constants (τ), which represent how quick a supercapacitor system can deliver stored energy at high power, are found to be 37 ms, 77 ms and 1.49 s for as synthesized MoS2 in 1 M H2SO4, 1 M Na2SO4 and 2 M KOH electrolytes, respectively. However, the capacity retention/coulombic efficiency of a MoS2 electrode in 1 M H2SO4, 1 M Na2SO4 and 2MKOH is found to be ∼ 30%/89%, 89%/94% and 86%/92%, respectively, after 1000 successive cycles at 2 A g−1. Our results suggest that a pristine flower like MoS2 is a good material to design a high performance supercapacitor device, which exhibits stable electrochemical performance in 1 M Na2SO4 electrolytes. The detailed electrochemical behavior of as synthesized samples has been thoroughly described in this paper. We believe our findings would be helpful in the designing of flower-like MoS2 based practical high performance supercapacitor devices.
Author N. Kanaujiya highly acknowledges MHRD (Govt. of India) for research fellowship. Author N. Kumar acknowledges the financial support from CSIR, New Delhi, India, for RA Fellowship under scheme No. 22(658)/14/EMR-II.
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