SiO2 Monomer-Triggered Self-Assembly of Hybrid CdTe Quantum Dots

Publication date: Available online 24 February 2017 Source:Chemical Engineering and Processing: Process Intensification Author(s): Yue Zhao, Simin Lu, Katarzyna Matras-Postolek, Ping Yang The self-assembly activity of quantum dots (QDs) including thioglycolic acid (TGA)-capped CdTe and hybrid SiO2-coated CdTe QDs into one- to three-dimensional (3D) nanostructures was reported using a slow growth process. SiO2 monomers from a sol-gel process and TGA play vital roles for the self-assembly. The hybrid SiO2-coated QDs were assembled into 1D nanotube, 2D nanosheets, and 3D nanoflowers by adjusting QD concentrations. It is found that the assemblies actually are CdTe@Cd-TGA-SiO2 complex hybrid nanostructures in which many well-separated CdTe QDs are uniformly distributed. Such assembly also occurred in an initial CdTe QD solution or in PBS and NaCl solutions. The assembly in the initial CdTe QD solution is accompanied by a hybrid SiO2 layer which resulted in red-shifted photoluminescence (PL) from green to yellow. Because of the domain growth of NaCl to form fractal structures through tip splitting and side branching dynamics, the hybrid SiO2-coated QDs were assembled into leaf morphology. As a result, the CdTe QDs with their in effective protection by hybrid Cd-TGA-SiO2 complex, these nanostructures show visually bright PL and retain the size-quantized properties of the QDs. These QD-based assemblies may be suitable for subsequent processing into quantum-confined materials an...
Source: Chemical Engineering and Processing: Process Intensification - Category: Chemistry Source Type: research