Antimonene nanosheets with enhanced electrochemical performance for energy storage applications

The antimonene is an exfoliated 2D nanomaterial of bulk antimony. It is a new class of 2D material for energy storage applications. In the present work, the antimonene was synthesized by the high energy ballmilling-sonochemical method. The structural, morphological, thermal and electrochemical properties of antimonene were comparatively analyzed with bulk antimony. The XRD analysis confirms the crystal structure and 2D structure of the antimonene as the peak shift was observed. The Raman spectra show the peak shift for Eg and A1g modes of vibration of antimony, which confirms the formation of antimonene. The SEM and HRTEM images depict the exfoliation of antimonene from bulk antimony. The thermal analysis unveiled the thermal stability of antimonene up to 400oC with only 3 % of weight loss. The XPS analysis reveals the formation of antimonene which is free from contamination. The electrochemical properties of antimony and antimonene were investigated by cyclic voltammetery (CV) and chronopotentiometric (CP) analysis using 2M KOH as an electrolyte. The antimonene exhibited the relatively high specific capacitance of 597 Fg-1 compared to ball-milled antimony (101 Fg-1) at the scan rate of 10 mVs-1. Moreover, the electrochemical impedance spectroscopic (EIS) analysis revealed that the antimonene has relatively low equivalence series resistance (RESR) and low charge transfer resistance (RCT) compared to bulk antimony which favors high electrochemical performance. The cyclic stability of the antimonene was studied for 3000 cycles and the result shows high cyclic stability. The electrochemical results demonstrated that antimonene is a promising material for energy storage applications.