A Simple Microwave Method for Synthesis of CdS Nanoparticles

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A Simple Microwave Method for Synthesis of CdS Nanoparticles Gholamreza Nabiyouni • Elaheh Azizi • Nazanin Nasrollahi

Received: 20 December 2012 Ó Springer Science+Business Media New York 2013

Abstract In this work a surfactant-free microwave method for preparation of CdS nanoparticles is reported. The effect of different parameters i.e. time and irradiation power, sulfur source and solvent on the morphology and the samples particle size have been investigated. The synthesized nanostructures were characterized by X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, Fourier transform infrared, photoluminescence and ultraviolet–visible spectroscopy. Keywords

Nanoparticles  Semiconductors  CdS

Introduction In the past decade, nanostructures of semiconductors became a focus of attention of researchers because of their unique properties and their potential applications in manufacturing of nanodevices. Among group II–VI semiconductors, CdS with a direct band gap of 2.42 eV is considered to be an excellent material for various optoelectronic applications in the visible range of the electromagnetic spectrum such as nonlinear optics, flat panel displays, light emitting diodes, lasers, and thin film transistors [1, 2]. CdS has been successfully synthesized into micro- and nanocrystals with different morphologies, such as nanoflowers, nanospheres, nanorods, and nanoparticles. Different methods were used to synthesize CdS e.g. solvothermal or hydrothermal synthesis, and precipitation process [1–4]. The microwave synthesis, which is quite fast, simple and very energy efficient, has been developed for a lot of applications. The effect of microwave energy on G. Nabiyouni (&)  E. Azizi Department of Physics, Faculty of Science, Arak University, 38156-8-8349 Arak, Iran e-mail: [email protected] N. Nasrollahi School of Chemistry, College of Science, University of Tehran, Tehran, Iran

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dielectric materials leads to what is generally known as dielectric heating, and the molecular dipoles (induced by microwaves) oscillate. This oscillation causes a higher rate of molecular collisions which generate heat. The microwave-assisted reaction has the advantage over the conventional synthesis methods. Microwaves Table 1 Summarized of different effective parameters on the various reactions

Sample no.

Solvent

Time (min)

Sulfur source

Power (W)

1

EG

3

TAA

340

2

EG

3

TAA

680

3

EG

3

TAA

850

4

EG

6

TAA

850

5

Water

3

TAA

850

6

EG

3

TU

850

7

EG

6

TU

850

8

EG

3

TU

680

9

Water

3

TU

850

10

EG

3

KSCN

680

11

EG

3

KSCN

850

12

EG

3

NaSCN

680

13

EG

3

NaSCN

850

14

EG

3

Na2S

680

15

EG

3

Na2S

850

Fig. 1 XRD patterns of the as-synthesized CdS prepared with a TAA sample no 1, b Tu sample no 6

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Synthesis of CdS Nanoparticles

are usually used for homogeneous heating of polar materials. While, in conventional heating (heating fluid, gas, burner or electrical heating) there is a temperature gradient between the h