Controllable synthesis: Bi2S3nanostructure powders and highly textured polycrystals

Abstract

Uniform Bi₂S₃ nanostructured powders with a preferential [001] orientation, including nanotubes, nanorods, and nanowires, were synthesized by hydrothermal synthesis using Bi(NO₃)₃ and Na₂S as raw materials, CO(NH₂)₂ as a pH modifier and ethanediol (C₂H₆O₂) as solvent. The growth mechanism of the Bi₂S₃ nanostructure in hydrothermal process was investigated. The precursor nanostructures of Bi₂S₃ single crystal powders were maintained in the Bi₂S₃ bulk after spark plasma sintering (SPS) at 673 K for 5 min, thereby the highest texture degree F_(h k 0) = 0.82 was reached for the sample sintered by using nanotubes as precursor powders, which is much higher than 0.18 for the sample sintered by using the powder prepared by mechanical alloying. The present result suggests that direct sintering of the orientated single crystal powders by applying SPS technique is easy to provide a highly textured Bi₂S₃ bulk, which benefits include enhanced electrical transport property.