One-pot microwave assisted approach for synthesis of CdSe/CdS core-shell quantum dots (QDs) and investigating optical properties

Abstract

In this work, CdSe QDs were synthesized using a microwave assisted method and chemical reaction between NaHSe, CdSO4 at the presence of TGA as capping molecule. Thereafter without CdSe extraction, CdS shell was grown subsequently around CdSe cores by a reaction based on the heat sensitivity of Na2S2O3 dissociation. Synthesized QDs were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV–Vis and photoluminescence (PL) spectroscopy. All of these analyzes confirmed formation of CdSe QDs and successfully growth of CdS shell on surface of CdSe to forming CdSe/CdS core-shell structure.

Rapid, controllable, one‐pot and room‐temperature aqueous synthesis of ZnO:Cu nanoparticles by pulsed UV laser and its application for photocatalytic degradation of methyl orange

“…The broad band at 3427 cm −1 is attributed to the O‐H stretching. For TGA‐capped ZnO and ZnO:Cu NPs vanishing of S‐H bond (2500 cm ‐1 ) in free TGA shows that H atom has been replaced by Zn at S‐H bond for formation of Zn‐S bond . Moreover, COOH characteristic peak of TGA at 1720 cm −1 vanished and two peaks at 1580 and 1385 cm ‐1 appeared corresponding to asymmetric and symmetric COO ‐ bonds, respectively .…”

“…XRD was performed by an advanced d8 Bruker system using Cu-k α radiation of wavelength λ = 0.15406 nm. UV-vis and PL spectra were vanishing of S-H bond (2500 cm -1 ) in free TGA [50,51] shows that H atom has been replaced by Zn at S-H bond for formation of Zn-S bond. [52] Moreover, COOH characteristic peak of TGA at 1720 cm −1 vanished and two peaks at 1580 and 1385 cm -1 appeared corresponding to asymmetric and symmetric COObonds, respectively.…”

CdSe and CdSe/CdS core–shell QDs: New approach for synthesis, investigating optical properties and application in pollutant degradation

“…Recently QDs have attracted much attention because of their unique electrical, optical and catalytic properties arising from quantum confinement effects . These unique properties have made them as promising candidates to be used in different applications such as solar cell, light emitting diode (LED), sensors and because of the degradation of various pollutants due to their high photosensitivity they can be used also as photocatalyst .…”

Reviving near infra‐red emission of Ag2S nanoparticles using interfacial defects in the Ag2S@CdS core–shell structure

“…have reported the preparation of different core–shell QDs such as CdTe@CdS, CdSe@CdS, CdSe@ZnS, and ZnSe@ZnS. Their results are interesting in terms of successful passivation of surface traps and enhancement in quantum efficiency of the emitting compound . Srinivasan et al .…”

“…Their results are interesting in terms of successful passivation of surface traps and enhancement in quantum efficiency of the emitting compound. [12][13][14] Srinivasan et al have synthesized NIR emitting Ag 2 S@SiO 2 core-shells with a notable 50 nm core size that was far from the quantum confinement regime of silver sulfide QDS. [15] Recently, we have reported a new pulsing irradiation method for the synthesis of Ag 2 S@ZnS QDs in water.…”