Meiling Ruan

Parameter control in the synthesis of ordered porous zirconium oxide

Abstract The ordered porous zirconium oxide with thermal stability up to 600°C has been synthesized by a surfactant-assisted route and a post-synthetic treatment with phosphoric acid. XRD, N 2 adsorption, HRTEM and UV–VIS spectroscopy were adopted for the characterization of the synthesized sample. It was shown that the parameter control, including the lower molar ratio of surfactant to zirconium resource (0.2–0.3), higher hydrothermal temperature (110°C), and the suitable H 3 PO 4 concentration (0.2–0.3 M), is important for the synthesis of high-quality zirconium oxide material with ordered pore structure.

Zinc oxide nanoarrays in nanoporous nickel phosphate with a huge blueshift ultraviolet-visible exciton absorption peak

Zinc oxide (ZnO) nanoarray prepared in the template of nanoporous nickel(II) phosphate Versailles Santa Barbara-1 (VSB-1) crystal exhibits an unusual ultraviolet-visible exciton absorption peak and an absorption shoulder. The exciton absorption peak at 266nm with the largest blueshift of 122nm up to now and narrow absorption peak with a full width at half maximum (FWHM) of about 34nm and the narrow photoluminescence emission peak 380nm with a FWHM of about 30nm, compared with that of bulk ZnO, are due to the quantum-confinement effects and the narrow size distribution of ZnO in the pores of VSB-1. This material presents potential applications in the theoretical research and fabrication of future quantum devices.

TEM and HREM characterization of hot-pressed zircon ceramics

Abstract The microstructure of hot-pressed zircon was examined by TEM and HREM with SAD. The results show that fabricated zircon ceramics consist of equiaxed zircon grains with some glassy particles in the zircon grains. HREM micrograph shows that the boundaries between two grains are free of glassy phase. However, two kinds of three-grain junctions are observed: one is devoid of any glassy phase, while the other has a glassy phase existing at the triple point. The relationship between microstructures of starting powder and zircon ceramics is discussed.

Acid-prepared mesostructures modified with TiO2 by a template–titanium tetrabutoxide displacement process

A simple template–metal alkyloxide displacement process has been used to modify the pore surface of acid-prepared mesostructures with titanium dioxide. Spectroscopic studies indicate that the complete removal of surfactant template and the pore surface modification could be simultaneously realised. Structural analyses show that the high surface area, large pore size, and well-ordered mesostructure could be fully retained after modification. Elemental analyses with X-ray energy-dispersive spectroscopy (EDS) and inductively coupled plasma–atomic emission spectroscopy (ICP–AES) give a Si/Ti molar ratio of around 18. It was therefore concluded that titanium dioxide has been homogeneously dispersed in the pore channels. Additionally, the simplicity of this process makes it suitable to be used for the pore surface modification of mesoporous thin films.

Synthesis of carbon nanostructures by ion sputtering

Abstract Carbon nanotubes and fullerene-like polyhedra have been synthesized in a surface layer of high-purity graphite by a 60 keV Ar + ion bombardment with normal incident angle under high vacuum conditions of ∼ 3 × 10 −7 Toor. Using high-resolution electron microscope (HRTEM) images, the termination of carbon-shell layers, seen on the tube and polyhedron surfaces or cone tips, suggests that the growth of the nanostructures possesses the characteristics of ion beam bombardment.

Preparation and properties of an ordered, uniform 0.9 nm Ag array assembled in a nanoporous VSB-1 by a simple soft chemical method

An ordered, homogeneously distributed and uniform 0.9 nm Ag array, which exhibits an unusual UV-vis surface plasmon resonance absorption peak at 355 nm with the largest blue-shift position and controllable intensity, has been successfully prepared by a simple soft chemical approach using the nanoporous VSB-1 as the template.

Preparation and characterization of manganese oxide confined within ordered porous zirconium oxide channels

Abstract Manganese oxide nanoparticles were synthesized within ordered porous ZrO 2 by using wet impregnation technique. The manganese-grafted sample was analyzed by XRD, N 2 adsorption, TEM, EDS, EPR, and UV–Vis diffusing reflectance spectroscopy. The experimental results show that the nanoparticles of manganese oxide could be successfully confined and randomly distributed into the pores of ZrO 2 . XRD and TEM investigations showed that the ordered porous host structure was still maintained. A significant enhancement of absorption peaks was detected, which was attributed to the host/guest effect.