Superior supercapacitor performance of Bi2S3 nanorod/reduced graphene oxide composites

• Published in: Dalton transactions : an international journal of inorganic chemistry 2020-12, Vol.49 (46), p.16993-17004
• Main Authors: Ghosh, Kalyan, Srivastava, Suneel Kumar
• Format: Article
• Language: English
• Subjects: Bismuth sulfides; Capacitance; Cycles; Dispersion; Graphene; Morphology; Nanocomposites; Nanoparticles; Nanorods; Sheets; Stability; Supercapacitors; Synergistic effect; X ray photoelectron spectroscopy; X ray spectra
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d0dt03594g

The present work is focused on the synthesis of bismuth sulfide (Bi2S3) nanorod/reduced graphene oxide (RGO) composites via a one-step hydrothermal method using GO and bismuth nitrate in 5 : 1, 3 : 1 and 2 : 1 weight ratios and their characterization. The morphological studies revealed the formation of homogeneously dispersed Bi2S3 nanorods on RGO sheets along with occasional wrapping in the Bi2S3 nanorod/RGO (3 : 1) composite. XRD, FTIR, Raman and XPS studies suggested the incorporation of Bi2S3 in RGO sheets. The galvanostatic charge–discharge measurements showed that the Bi2S3 nanorod/RGO (3 : 1) composite exhibited the highest specific capacitance (1932 F g−1) at 1 A g−1 in the presence of 2 M aqueous KOH in a three-electrode cell. This is ascribed to the enhanced contact area between metal sulfide nanoparticles and RGO, increased conductivity and synergistic effect of Bi2S3 and RGO. The optimized Bi2S3 nanorod/RGO (3 : 1) composite also maintained an excellent cycling stability with ∼100% capacitance retention after 700 cycles. It is noted that the supercapacitor performance of the Bi2S3 nanorod/RGO (3 : 1) composite was better than group V and VI metal chalcogenides and their nanocomposites reported in several previous studies.