Probing the growth mechanism of PbTe hopper-like crystal and ultra-long nanowires with rough surface synthesized through acetone-assisted solvothermal method

摘要

In this paper, uniform and massive PbTe hopper-like crystals with internal steps and ultra-long nanowires have been synthesized with acetone acting as a solvent and retarder. The as-obtained products were well investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM). A series of experiment conditions including reaction temperature, time, the ratio of solvent, have been performed in detail. Concentration of acetone, KOH and EDTA in the reaction mixture play a vital role for controllable structures and morphologies. Based on a series of the time-dependent experimental data, the possible growth mechanisms have been proposed to elucidate the formation of hopper-like crystals and nanowires with rough surface. This simple synthetic route may be extended to prepare other PbTe-based thermoelectric nanomaterials, such as AgPb_mMTe_(m+2) (M = Sb, Bi, La).