Preparation of fluorescent tellurium nanowires at room temperature

We have demonstrated a simple approach to the synthesis of fluorescent trigonal tellurium (t-Te) nanowires in aqueous solution at room temperature. The t-Te nanowires were prepared from the reduction of tellurium dioxide (TeO2) with concentrated hydrazine solution through deposition of Te atoms that were reduced from telluride ions (Te2-) and dissolved from amorphous tellurium (a-Te) nanoparticles onto t-Te nanocrystallines. By carefully controlling the growth time from 40 to 120 min, we prepared different sizes of t-Te nanowires; the length changed from 251 to 879 nm, while the diameter only grew from 8 to 19 nm. The absorption wavelength against the diameter of t-Te nanowires displays the diameter dependence of band I (< 300 nm). On the other hand, the absorption wavelength against the length of t-Te nanowires displays the length dependence of band II (> 600 nm). By increasing the size of t-Te nanowires, their absorption is under a red shift. For example, the maximum wavelengths of the absorption bands for the t-Te nanowires with the lengths of 251 nm are 271 and 602 min, while those for 879 nm t-Te nanowires are at 280 and 687 nm, respectively. Deconvolution of the photoluminescence profile for t-Te nanowires obtained at 120 min yields four Gaussian peaks centered at 334, 397, 460, and 507 nm.