Selective oxidation mediated synthesis of unique Se_xTe_y nanotubes, their assembled thin films and photoconductivity

One-dimensional hollow nanostructures have potential applications in many fields and can be fabricated using various methods. Herein, a selective-oxidation route for the synthesis of unique Te_xSe_y nanotubes (STNTs) with a controlled morphology using Te_xSe_y@Se core–shell nanowires (TSSNWs) as a template is reported. Because of the lower redox potential of TeO₂/Te compared to that of H₂SeO₃/Se, the Te in TSSNWs can be preferentially oxidized by an appropriate oxidant of HNO₂ to form STNTs. The inner diameters and wall thicknesses of the STNTs can be tuned by modulating the core diameters and shell thicknesses of the TSSNWs, respectively. The STNTs can be assembled into a monolayer composed of well-arranged nanotubes using the Langmuir–Blodgett technique. A device based on films stacked with 10 STNT monolayers was fabricated to investigate the photocoductivity of the STNTs. The STNTs exhibited a good photoresponse over the whole ultraviolet–visible spectrum, revealing their potential for application in optoelectronic devices.