Growth of Au nanocrystals on CdS nanorods

Abstract

Nanorods of S2 rich CdS were synthesized by a reaction of excess S versus Cd precursors in the presence of ethylene diamine. The photoluminescence (PL) emission from the S 2 rich CdS nanorods was broad with a peak at ~710 nm, which was 40 nm longer in wavelength than the PL peak from Cd 2+ rich CdS (~670 nm) nanorods. The influence of surface electron or hole trap states on the luminescent pathway of CdS nanorods will be discussed to explain these shifts in wavelength. Nanocrystals of Au ~2 nm in size were grown on S 2 rich surfaces of CdS nanorods. Significant luminescence quenching was observed from the Au nanocrystals on the CdS nanorods due to interfacial charge separation. Charge separation by the Au nanocrystals on the CdS resulted in enhanced photocatalytic degradation of Procion red mix-5B (PRB) dye in an aqueous solution under UV light irradiation.

Light-Controlled One-Sided Growth of Large Plasmonic Gold Domains on Quantum Rods Observed on the Single Particle Level

“…6000 Au atoms per rod) were added to CdSe/CdS nanorods in a mixture of ethanol and chloroform. (b) Diagram of the Fermi level of the gold domain (left), the conduction and valence band edges of CdS nanorods ( E CB , E VB , respectively) and the first oxidation level of ethanol before irradiation. , The bulk Fermi-level of gold (*) is slightly shifted in small gold domains (**) …”

“…The blueshift is due to an accumulation of negative charges in the gold domain, increasing its electron density and plasmon frequency. 23 The saturation indicates equilibrium of the metal's Fermi level and the semiconductor conduction band 35,41 The bulk Fermi-level of gold (*) is slightly shifted in small gold domains (**). edge.…”

Preparation, Surface and Crystal Structure, Band Energetics, Optoelectronic, and Photocatalytic Properties of AuxCd1−xS Nanorods

“…These modified physicochemical properties were attributed to the charges eparation ability upon photoexcitation, uniform dispersion of Au 3 + ions, surface structurald istortion, extra electrons imparted, and band edge potentials suitable for ready charge transfer to reactant species. In at ypical procedure, [40] (0.4Àx)mmol Cd(NO 3 )·4 H 2 Oa nd x mmol of HAuCl 4 ·x H 2 Ow ere mixed thoroughly in 10 mL of ethylenediamine prior to the addition of thiourea (0.8 mmol) and refluxed at 140 8Cf or 10 h. The products were obtained by centrifugation, and were washed with distilled water and ethanol and then dried at 60 8Cf or 1h.…”

Morphological transition of vertically aligned one-dimensional zinc oxide

“…So far, various kinds of 1D nanostructures have been synthesized, including Si, Ge, GaN, GaAs, InAs, ZnO, etc. [2][3][4][5]. Among them, 1D ZnO nanostructures have attracted special attention due to their unique properties such as high crystallinity, wide direct band gap energy (3.37 eV), large excitation binding energy (60 meV), piezoelectricity, and biocompatibility [6].…”