Syntheses, Growth Mechanism, and Optical Properties of [001] Growing Bi2S3 Nanorods

Uniform Bi2S3 nanorods growing along [001] have been synthesized from the precursor of Bi[S2CN(C8H17)(2)](3) by two different approaches: solventless and solvothermal methods. The structure, morphology, and formation process of the nanorods have been investigated by SEM, TEM, HRTEM, XRD, and EDX analyses. The growth direction is intrinsically governed by the crystal structure motif and the high surface energy of the (001) plane of orthorhombic Bi2S3 according to the CASTEP calculations. Besides, some important factors that influence the growth of Bi2S3 nanorods, such as the length of alkyl group in the precursor and the reaction temperature are investigated. The optical band gap of the as-synthesized Bi2S3 nanorods is measured to be 1.50 eV indicating a slightly blue shift owing to the quantum size effect.