Characterization and photonic absorption of hierarchical tree-like CdS nanostructure synthesized by solvothermal method

Abstract

Hierarchical tree-like wurtzite CdS nanostructure was successfully synthesized by the 200°C and 24 h solvothermal reaction of cadmium nitrate and thiourea as starting materials in 1:1 volume ratio of diethylenetriamine and ethylenediamine as a mixed solvent. Phase and morphology of the as-synthesized CdS product were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM), including its photonic absorption by UV-visible spectroscopy. XRD spectrum and TEM image showed hexagonal wurtzite CdS structure with a 1-2 μm prototypical cluster, composed of a number of limbed nanorods. Its Raman spectrum was specified as the first-order (1LO) and second-order (2LO) longitudinal optical phonon modes at 298 and 599 cm- 1. UV-visible spectrum shows an absorption peak centered at around 489 nm, assigned as the excitonic transition, blue shifted comparing to its bulk. © 2012 Elsevier B.V. All rights reserved.