Synthesis and Characterization of Highly Luminescent CdS@ZnS Core−Shell Nanorods

Abstract

Highly luminescent CdS-core ZnS-shell nanorods stabilized by mercaptopropionic acid in water were synthesized wet-chemically and characterized by measuring photoluminescence spectra and kinetic profiles as well as absorption spectra, diffraction patterns, and electron microscope images. Photoluminescence from CdS nanorods 22 nm in diameter shifts to the blue by as much as 2.8 nm and increases as high as 1.8 times with the thickness of the passivating ZnS shell, whereas the luminescence lifetime of 1:1 CdS@ZnS coreshell nanorods is shorter by 1.6 times at 550 nm than that of bare CdS nanorods. Inorganic passivation by ZnS gives rise to the intensity increase and the lifetime decrease, while alloy formation with ZnS mainly brings about the blue shift.

Synthesis, characterization and visible-light driven photocatalysis by differently structured CdS/ZnS sandwich and core–shell nanocomposites

“…The presence of diffraction peaks corresponding to only CdS and complete absence of diffraction peaks due to ZnS core predict the core-shell structure of the ZnS/CdS sample. This is in agreement with earlier reports on core-shell structures, that as the shell thickness increases, the diffraction pattern of the shell material predominates [23][24][25][26][27][28][29][30][31][32].…”

“…The optical properties of various semiconductor QDs may also be improved by coating them with a shell of a second higher band gap semiconductor, resulting in core-shell type-I systems [25,26]. Core-shell nanocrystals contain at least two semiconductor materials in an onion-like arrangement [27].…”

CdS‐Encapsulated TiO2 Nanotube Arrays Lidded with ZnO Nanorod Layers and Their Photoelectrocatalytic Applications

“…[18][19][20][21][22][23] This is due to the fact that the photogenerated electrons from CdS could be injected into the conduction band of TiO 2 , resulting in the PEC reaction. [24,25] Various structures of TiO 2 /CdS coupling systems have been reported in the literature, such as TiO 2 /CdS composite nanofilms, [26][27][28][29] NPs, [30] NRs, [31][32][33][34][35][36] and other TiO 2 /CdS hybrids. [37][38][39] The results confirmed the sensitization of CdS for TiO 2 .…”

Fabrication, spectroscopy, and dynamics of highly luminescent core–shell InP@ZnSe quantum dots

“…Thus, to improve the photoluminescence of InP quantum dots, surface phosphorous atoms lying at the origins of trap sites were removed by being etched with HF or nanocrystals were passivated with shell materials that have wider band gaps [17,[24][25][26][27]. The type-I core-shell semiconductor, where the shell material having a wider band gap is over grown onto the core material having a narrower band gap, reduces the non-radiative recombination effectively by confining the wave function of an electron-hole pair to the interior of the core crystal [28][29][30]. In such a core-shell nanocrystal, the shell provides a physical barrier between the optically active core and the surrounding medium, thus elevating stability against various chemical and physical changes.…”