Cadmium sulphide (CdS) nanostructures were synthesized via a simple chemical precipitation method by using Mercaptoethylamine hydrochloride (MEA) as a capping agent. Fine tuning of the nanosized CdS material was carried out by controlling the amount of the capping agent. The synthesized CdS nanostructures were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis diffuse reflectance spectroscopy (DRS). Optical absorption spectroscopy was mainly used to measure the band gap and size of the CdS nanostructures. The photocatalytic activities of the synthesized samples were investigated for degradation of methylene blue (MB) under blue LED (3 W) and solar light irradiation. (C) 2013 Elsevier B.V. All rights reserved.