Polymer-assisted hydrothermal synthesis of Bi2S3 nanostructured flowers

Nanostructured Bi₂S₃ was hydrothermally produced from Bi₂O₃ and thiocarbohydrazide in acidic solutions containing PVA, PEG and PVP. By using XRD, SAED and Raman spectrometry, the products were orthorhombic Bi₂S₃, with four vibration modes at 139.6, 253.7, 310 and 968.9 cm⁻¹. The phase was also in accordance with the diffraction patterns obtained by simulation. SEM, TEM and HRTEM show that the products are clusters of nanorods produced in polymer-free solution, and nanostructured flowers of nanospears, nanorods and nanoplates in the respective PVA-, PEG- and PVP-added solutions, with their growths in the same direction of [0 0 1]. A formation mechanism was also proposed according to their phase and morphologies.