Tailoring the morphology, crystalline structure, and electrochemical properties of nanostructured Bi2S3 using various solvent mixtures

Abstract

Among novel nanostructured materials, transition metal chalcogenides (i.e., sulfides and selenides) emerged as promising candidates due to their unique electrochemical properties. The following study presents a facile synthesis approach of Bi₂S₃ nanostructures using solvent mixtures of ethanol and water with different volume ratios and ammonium sulfide as a sulfur precursor. The resultant bismuth sulfides were characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen sorption at 77?K. The adjustment of the solvent mixture revealed the possibility of customizing the crystalline structure from amorphous to fully crystalline, as well as the morphology of the Bi₂S₃, which subsequently influenced on their electrochemical properties. Bi₂S₃ synthesized in a solvent mixture of ethanol-to-water volume ratio 1:2 (Bi₂S₃-EW12) exhibited almost fully crystalline structure and nanoplatelet-like morphology, which translated to the best electrochemical performance. Bi₂S₃-EW12 achieved specific capacity of 748?C?g^?1 in an aqueous 6?mol?L^?1 KOH electrolyte and maintained the highest capacity value at a large current density of 20?A?g^?1.