Aqueous synthesis and characterization of CdS quantum dots capped with some amino acids and investigations of their photocatalytic activities

The current study examines the influence of some amino acids such as alanine, histidine, and serine as stabilizers in the synthesis of CdS quantum dots. The CdS quantum dots (QDs) exhibited strong absorption and photoluminescence properties upon UV vis wavelength in the region from 200 nm to 800 nm. Structural and spectroscopic properties of the synthesized CdS QDs were characterized by absorption and fluorescence spectroscopy, X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy. Influence of some parameters on fluorescence intensity of CdS QDs including the precursor ratio, type of modifier, temperature, and initial pH of the reaction was thoroughly studied. Results indicated that the pH and the type of modifier that used played crucial roles in determining luminescence properties of the synthesized CdS nanoparticles. Generally, the luminescence intensity can be enhanced significantly when the CdS QDs are illuminated by room light or sunlight. Also, results specified that the synthesized CdS QDs were capable of effectively degrading organic dyes such as alizarin under visible light irradiation and exhibiting good recycling stability during photocatalytic experiments. (C) 2014 Elsevier B.V. All rights reserved.