Ionic liquids-assisted synthesis and electrochemical properties of Bi2S3 nanostructures

Morphology control of bismuth sulfide (Bi2S3) nanostructures, from one-dimensional nanorods with various aspect ratios, to various kinds of two-dimensional nanofabrics (dense nanofabrics and spark nanofabrics) to three-dimensional urchin-like microspheres and crossed nanofabrics, has been achieved via an ionic liquids-assisted hydrothermal route, by adjusting the active state of the BiOCl, the characteristics and concentration of the ionic liquid used and the reaction temperature. Reasonable growth mechanisms for the Bi2S3 with different morphologies are proposed, based on active state of the intermediate BiOCl, characteristics of the ionic liquids used and the crystal growth habits of Bi2S3. More importantly, we introduce the concept of two different states of the intermediate BiOCl (active BiOCl and inert BiOCl) to explain the growth mechanisms of nanofabrics, nanorods and urchin-like microspheres, from different crystal growth processes. Moreover, electrochemical measurements demonstrate that Bi2S3 nanofabrics and urchin-like microspheres possess higher initial Li intercalation capacity than graphitic materials (372 mA h g(-1)), and their cyclic performances are highly dependent on their morphologies.