Shape-controlled synthesis of tellurium 1D nanostructures via a novel circular transformation mechanism

A facile surfactant-assisted solvothermal method had been employed to selectively synthesize single-crystalline tellurium nanowires and nanotubes and realize the circular transformation of wirelike and tubelike nanostructures by means of tuning the reaction time. Nanowires with an average diameter of about 23 nm were fabricated after 16 h; however, the reaction time was elongated to 28 h, these nanowires transformed into needlelike nanotubes ranging from 15 to 45 mu m in length and 250-320 nm in wall thickness with cuneiform groovelike nozzles. Surprisingly, as the time continued to 45 h, nanowires with diameters in the range of 10-20 nm were obtained finally. What's more, the influence of the amount of PVP, ethanol amine, and the reaction temperature on the crystal morphology and controlled synthesis had been studied systematically. Through the exact observation of time-dependent samples in the transformation process, a micellar template-based wire-self-assembly mechanism was proposed to illuminate the transformation of from nanowires to nanotubes, in which the rodlike micelle made up of PVP served as the soft template of wire arrangement, and a nannotube redissolution-growth mechanism was proposed for the final formation of nanowires.