Meng-Yuan Li

In situ source–template-interface reaction route to hollow ZrO2 microspheres with mesoporous shells

Hollow ZrO(2) microspheres with mesoporous shells have been synthesized by a novel hydrothermal reaction of zirconium oxychloride in the presence of urea, hydrochloric acid, and ethanol. The morphology and shell thickness of the hollow microspheres can be controlled by varying synthesis conditions. After calcination at high temperature, the morphologies of the hollow microspheres are essentially preserved. Pt catalyst supported on the hollow calcined ZrO(2) microspheres exhibits more excellent catalytic performance in CO oxidation than those on ZrO(2) powders derived from conventional precipitation methods.

Synthesis of ZrO2 nanowires by ionic-liquid route

Zirconia precursor nanowires were synthesized via the solvothermal reaction of zirconium tetra-n-propoxide Zr(OPr(n))(4) with ethylene glycol and 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid at 160 degrees C. The as-synthesized nanowires were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetric (TG-DSC) analysis, and infrared spectroscopy (IR), etc. The length of the as-synthesized nanowires reaches approximately 20 mum, and the width approximately 50 nm, giving an aspect ratio of a few hundreds. Upon calcination at elevated temperatures, the zirconia precursor nanowires transform from relative dense structure into highly porous ZrO(2) nanowires consisting of interconnected nanocrystallites; in addition the length of the nanowires is greatly reduced. Cyclic voltammetry measurement shows that the modification of the graphite electrode with the ZrO(2) nanowires greatly enhances sensitivity of the detection of vanadium, suggesting that ZrO(2) nanowires may find important applications in vanadium(V) determination using electroanalytical methods with chemically modified electrode technique.

Simple Synthesis of Carbon/Tin Oxide Composite as Anodes for Lithium-Ion Batteries

Several carbon/tin oxide (C/Sn0 2 ) composite anode materials are prepared through a novel and simple solution route. Powder x-ray diffraction and energy dispersive analysis of x-ray measurements confirm that the nanosized SnO 2 particles are homogeneously dispersed in the carbon matrix. Both the content of Sn0 2 and the carbonization temperature play an important role on the electrochemical performance of the C/SnO 2 composites. The C/Sn0 2 anode material with 47% SnO 2 , carbonized at 600°C, has the optimal electrochemical performance. This material exhibits an initial charge capacity of 643 mAh g ―1 and an average reversible capacity of 518 mAh g ―1 during 50 cycles at a current density of 50 mA g ―1 .