Composites of Te nanorods and TeO_2 nanoparticles: chemical synthesis in an alkaline condition, characterization and photovoltaic measurements

摘要

Composites of Te nanorods and TeO_2 nanoparticles have been successfully synthesized via a reduction chemical method in an alkaline condition. In this method, TeCl_4 and N_2H_4·H_2O used as starting materials were heated at 70 ℃ for 10 min in the presence of NaOH solution. To study the effect of NaOH on the formation mechanism of the products, the experiment marked as blank test was carried out without using NaOH solution. X-ray powder diffraction (XRD) analysis of the product obtained from the blank test showed that Te nanorods could be only formed by using TeCl_4 and N_2H_4·H_2O in the absence of NaOH at the same conditions. In addition, the effect of NaOH concentration on the morphology and chemical composition of the composites was investigated. Based on the XRD results, it was found that the production of the TeO_2 nanoparticles increased by increasing the concentration of NaOH solution. Besides, the electron microscopy images of the products indicated that the lengths of the Te nanorods increased by increasing the concentration of NaOH solution. The final products have been characterized by XRD, SEM and TEM. We have also studied the photocurrent density-voltage (J-V) curve of the as-synthesized composites.