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

Abstract

In this work, CdSe quantum dots (QDs) were synthesized by a simple and rapid microwave activated approach using CdSO , Na SeO as precursors and thioglycolic acid (TGA) as capping agent molecule. A novel photochemical approach was introduced for the growth of CdS QDs and this approach was used to grow a CdS shell around CdSe cores for the formation of a CdSe/CdS core-shell structure. The core-shells were structurally verified using X-ray diffraction, transmission electron microscopy and FTIR (Fourier-transform infrared (FTIR)) spectroscopy. The optical properties of the samples were examined by means of UV-Vis and photoluminescence (PL) spectroscopy. It was found that CdS QDs emit a broad band white luminescence between 400 to 700 nm with a peak located at about 510 nm. CdSe QDs emission contained a broad band resulting from trap states between 450 to 800 nm with a peak located at 600 nm. After CdS shell growth, trap states emission was considerably quenched and a near band edge emission was appeared about 480 nm. Optical studies revealed that the core-shell QDs possess strong ultraviolet (UV) - visible light photocatalytic activity. CdSe/CdS core-shell QDs, showed an enhancement in photodegradation of Methyl orange (MO) compared with CdSe QDs.

RETRACTED: CdSe Quantum Dot Nanoparticles: Synthesis and Application in the Development of Molecularly Imprinted Polymer-Based Dual Optical Sensors

“…Besides, the chemical composition of CdSe quantum dot nanoparticles was studied by FTIR spectrum in the range of 400–4000 cm –1 . Figure b shows the bands at 2926, 1572, and 1386 cm –1 related to −CH 2 , asymmetric COO – , and symmetric COO – , respectively. , The bands at 1106 and 695 cm –1 could be assigned to the O–H bending vibration and the C–S stretching vibration . The absorption band at 448 cm –1 is ascribed to the stretching vibrations of the Cd–Se bond …”

“…Figure 1b shows the bands at 2926, 1572, and 1386 cm −1 related to −CH 2 , asymmetric COO − , and symmetric COO − , respectively. 34,35 The bands at 1106 and 695 cm −1 could be assigned to the O−H bending vibration 36 and the C−S stretching vibration. 37 The absorption band at 448 cm −1 is ascribed to the stretching vibrations of the Cd−Se bond.…”

InP/ZnS quantum dots synthesis and photovoltaic application

“…As nanosize QDs exhibit a high surface to volume ratio, surface states play a critical role in their physical and chemical behaviour and can significantly influence the absorption and luminescent properties. A wide list of recent reports confirm the potential for applications of QDs in photovoltaics (Beard et al 2014;Hillhouse and Beard 2009), light emitting devices (Zhang et al 2016;Ma et al 2013;Kagan et al 2016) and in many environmental (Tayebi et al 2016;Abbasi et al 2017) and biomedical experiments (Khan et al 2017;Liu et al 2018;Kulchat et al 2018;Biju et al 2010).…”

Biosynthesis of Cu-In-S Nanoparticles by a Yeast Isolated from Union Glacier, Antarctica: A Platform for Enhanced Quantum Dot-Sensitized Solar Cells

“…Their physical, chemical, and optical properties, including emission and absorption, can be finely tuned through the quantum confinement effect, which is dependent on size and chemical composition [ 7 ]. This versatility has led to their application in diverse fields, such as solar cell sensitization [ 8 ], organic pollutant degradation [ 9 ], hydrogen generation [ 10 ], bioimaging [ 3 ], and more.…”