Synthesis of hydrothermally derived boron and sulfur-incorporated reduced graphene oxide sheets for supercapacitor applications

The combination of boron and sulfur incorporated reduced graphene oxide (B/S-rGO) was synthesized by a simple hydrothermal technique using a novel and single source of thiophene-2 boronic acid pinacol ester. Structural and functional groups of the synthesized materials were analyzed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. The Raman analysis revealed the defective structure after incorporating sulfur and boron elements into rGO. The morphological and the presence of elements in the synthesized material were analyzed by scanning electron microscopy, transmission electron microscopy and elemental mapping analysis. The chemical states and chemical composition of B/S-rGO were observed by X-ray photoelectron spectroscopy (XPS) analysis. The electrochemical performance of the prepared material was studied using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance analysis. GCD studies were performed for B/S-rGO electrode material in an aqueous 1 M H2SO4 electrolyte. The prepared material showed a high specific capacitance of 345 Fg(-1) at 1 Ag-1 in a three-electrode configuration. B/S-rGO based device exhibited 97 Fg(-1) of specific capacitance at 1 Ag-1 in a symmetric two-electrode configuration. B/S-rGO based symmetric device showed a high energy density of 13.4 Whkg(-1) at 249 Wkg(-1) and more than 96% capacity retention after 5000 cycles.