Preparation by Hydrothermal Techniques in a Tungstosilicate Acid Solution System and Optical Properties of Tellurium Nanotubes

Single-crystalline tellurium nanotubes can be easily synthesised by a simple hydrothermal, economical and green chemical route. The tungstosilicate acid (TSA) serves as not only an effective reducing agent but also a new morphology-directing agent for tellurium nanotubes from sodium tellurate (Na2TeO3) precursor powders. Scanning electron microscopy images show that most of the tellurium nanotubes have sloping cross-sections and open ends with outer diameters of 100-500 nm, wall thicknesses of 30-100 nm and lengths of 30-50 mu m. A few Te nanotubes have hexagonal cross-sections. Te nanotubes grow along the [001] direction and have excellent crystallinity. The synthetic conditions also investigated for the tellurium nanotubes were molar ratio of sodium tellurate to TSA, pH of reaction solution and reaction temperature. The optical properties of the t-Te nanotubes have been investigated. A possible mechanism for the growth of tellurium nanotubes has been discussed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)