Hydrogel templated CdS quantum dots synthesis and their characterization


ŞAHİNER N. , SEL K. , Meral K., ONGANER Y., Butun S., ÖZAY Ö. , ...More

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, vol.389, pp.6-11, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 389
  • Publication Date: 2011
  • Doi Number: 10.1016/j.colsurfa.2011.09.006
  • Title of Journal : COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
  • Page Numbers: pp.6-11

Abstract

This work reports a facile method for preparation of CdS quantum dots (Q-dots), using a crosslinked hydrophilic p(AMPS) hydrogel network by absorption of Cd(II) ions and sequential precipitation with aqueous Na2S within the network at room temperature. The TEM images revealed that prepared CdS Q-dots were distributed throughout the p(AMPS) hydrogel network and their sizes were about 5 nm. The amount of inorganic material inside p(AMPS) hydrogel was determined by TGA measurements to be 16.9% by weight. Additionally, the Cd and S amounts inside the p(AMPS) network were determined by dissolution of particles with HCl (three treatments with 3 M HCl) and by using ICP-AES (for Cd) and an elemental analyzer (for S). From UV–visible absorbance measurements, optical energy gap values of 5.1 ± 0.1 eV for p(AMPS) and 2.4 ± 0.05 eV for p(AMPS)–CdS were determined. From the fluorescence spectrum of the p(AMPS)–CdS hydrogel, the peak energy was observed at 2.30 eV. The in situ prepared Q-dots were recovered from hydrogel matrices by placing the p(AMPS)–CdS composite in purified water.

This work reports a facile method for preparation of CdS quantum dots (Q-dots), using a crosslinked hydrophilic p(AMPS) hydrogel network by absorption of Cd(II) ions and sequential precipitation with aqueous Na2S within the network at room temperature. The TEM images revealed that prepared CdS Q-dots were distributed throughout the p(AMPS) hydrogel network and their sizes were about 5 nm. The amount of inorganic material inside p(AMPS) hydrogel was determined by TGA measurements to be 16.9% by weight. Additionally, the Cd and S amounts inside the p(AMPS) network were determined by dissolution of particles with HCl (three treatments with 3 M HCl) and by using ICP-AES (for Cd) and an elemental analyzer (for S). From UV-visible absorbance measurements, optical energy gap values of 5.1 +/- 0.1 eV for p(AMPS) and 2.4 +/- 0.05 eV for p(AMPS)-CdS were determined. From the fluorescence spectrum of the p(AMPS)-CdS hydrogel, the peak energy was observed at 2.30 eV. The in situ prepared Q-dots were recovered from hydrogel matrices by placing the p(AMPS)-CdS composite in purified water. (C) 2011 Elsevier B.V. All rights reserved.