Synthesis and Cathodoluminescence of Morphology-Tunable SiO₂ Nanotubes and ZnS/SiO₂ Core−Shell Structures Using CdSe Nanocrystals as the Seeds

Abstract

High-density, ultralong SiO 2 nanotubes were successfully synthesized by a one-step thermal evaporation process using CdSe nanocrystals as the seeds. The as-synthesized products were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, and cathodoluminescence. Varying experimental parameters results in the formation of additional SiO 2 -based nanostructures, such as flowerlike SiO 2 nanotubes and ZnS/SiO 2 core-shell structures. On the basis of these observations, a template-based growth mechanism was proposed for the growth of these nanostructures. Furthermore, the stable and strong visible-light emission properties are of significant interest for their potential applications in future integrated devices.

Morphology‐ and Color‐Tunable Bright Fibers with High Concentration of CdTe Nanocrystals Assembled through Sol–Gel Reaction

“…[1][2][3][4][5] In particular, 1D materials constructed of various types of nanocrystals (NCs) are becoming a hot research topic because these materials are expected to have novel properties. [6][7][8][9][10] Progress has been made in synthesizing 1D nanostructures using semiconductor NCs. [7][8][9][10] However, fibers made of these materials generally do not exhibit intense photoluminescence (PL) because the surface states of the NCs change during processing.…”

“…[6][7][8][9][10] Progress has been made in synthesizing 1D nanostructures using semiconductor NCs. [7][8][9][10] However, fibers made of these materials generally do not exhibit intense photoluminescence (PL) because the surface states of the NCs change during processing. Here, we report on intensely luminescent fibers prepared by the self-assembly of hybrid SiO 2 -coated CdTe NCs, SiO 2 monomers, and a complex mixture of Cd 2þ and thioglycolic acid (TGA).…”

“…Inorganic fibers have so far been prepared using a variety of approaches including high-temperature, [10] reverse micelle synthesis, [11] hydrothermal, [12] and template methods based on either hard mesoporous materials (hard templates) [13] or soft selforganized nanostructures (soft templates). [14] Small organic molecules (for example, 2,4,5-triphenylimidazole) have been used as a soft template to prepare single crystalline submicrotubes by using non-covalent intermolecular interactions, such as hydrogen bonding, p-p interactions, van der Waals contacts, and charge transfer interactions.…”

Synthesis of Inorganic Nanotubes

“…CdSe nanocrystals are used as seeds in a one-step thermal evaporation process to prepare long, high density SiO 2 nanotubes. [79] SiO 2 nanotubes generally have smooth surfaces, uniform thickness, and round cross sections of both the interiors and exteriors which are amorphous in nature.…”

Inorganic Nanotubes and Nanowires

“…CdSe nanocrystals are used as seeds in a one-step thermal evapouration process to prepare long, high density SiO 2 nanotubes. [77] High purity SiO 2 nanotubes are obtained by using track-etched membrane templates involving O 2 plasma treatment. Oxygen plasma pretreatment ensures pore-filling of the precursor solution and covalent bonding between template and precursor, while pyrolysis of the template-nanostructure composite completely removes organics and produces inorganic nanostructures.…”