Structural, optical and morphological properties of CdS nanoparticles synthesized using hydrazine hydrate as a complexing agent

Abstract

The complexing agent plays an important role in the synthesis of nanoparticles. Here we report on the synthesis of nanocrystalline CdS by a simple chemical precipitation method using hydrazine hydrate as a complexing agent. The reaction was carried out in an aqueous medium at constant temperatures with continuous stirring. Samples were grown at various temperatures ranging from 40 to 70 °C. The as-grown samples were characterized using powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM/HRTEM),Fourier transform infrared spectroscopy (FTIR),UV-visible spectroscopy and energy dispersive analysis of X-rays (EDX). XRD results confirm the formation of nanocrystalline CdS with the crystallite size increasing from 3 to 15 nm as the growth temperature is increased from 40 to 70 °C. TEM/HRTEM images show that the grain size of the CdS particles is in the range 5–10 nm, the grain size increasing with growth temperature, agreeing with XRD results. The optical band gaps of the samples are blue shifted as the growth temperature is reduced (resulting in a decrease in the crystallite size), confirming the quantum confinement of electrons in the CdS nanoparticles. The results show that the structural and optical properties of the CdS nanoparticles can be controlled by the use of hydrazine hydrate.