Controlled synthesis of tellurium nanostructures from nanotubes to nanorods and nanowires and their template applications

In the present study, we report a facile hydrothermal route developed to synthesize various 1D tellurium nanostructures including nanotubes, nanowires, and nanorods on a large scale. Te nanotubes with a tunable diameter from 200 nm to 2 μm are fabricated in NaOH solution. With poly(vinyl pyrrolidone) as the surfactant, ultrathin Te nanowires with a diameter of 5-8 nm are synthesized in NaOH solution. However, in both cases, only Te nanorods are obtained if NaOH is not added. The formation of Te nanotubes is attributed to the depletion of Te atoms at the surface of seeds. The influence of the reaction conditions including pH value, reaction temperature, reducing agent, and reactant concentration on the size and morphology of the Te nanostructures is investigated and the structural evolution with different growth rate is illustrated. A reduction reaction rate controlled growth mechanism has been proposed for the variable nanostructures. In addition, the obtained Te nanostructures are ideal templates to synthesize other Te-related nanocompounds, which is demonstrated by the synthesis of ultrathin Ag₂Te nanowires through the direct reaction of ultrathin Te nanowires with AgNO₃ at room temperature.