Synthesis of Tungsten-Doped Vanadium Dioxide Using a Modified Polyol Method Involving 1-Dodecanol.

The doping of tungsten into VO (M) via a polyol process that is based on oligomerization of ammonium metavanadate and ethylene glycol (EG) to synthesize a vanadyl ethylene glycolate (VEG) followed by postcalcination was carried out by simply adding 1-dodecanol and the tungsten source tungstenoxytetrachloride (WOCl). Tungsten-doped VEGs (W-VEGs) and their calcinated compounds (WVO) were prepared with varying mixing ratios of EG to 1-dodecanol and WOCl concentrations. Characterizations of W-VEGs by powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and infrared and transmittance spectroscopy showed that tungsten elements were successfully doped into WVO, thereby decreasing the metal-insulator transition temperature from 68 down to 51 °C.

Designable Phase Transition Temperature of VO₂ Co-Doped with Nb and W Elements for Smart Window Application.

Monoclinic vanadium dioxide (VO₂ (M)) particles co-doped with niobium and tungsten, with potential application in smart windows, were synthesized by hydrolysis and subsequent thermal decomposition of vanadyl sulfate. All the doped VO₂ particles exhibited a monoclinic crystalline phase and the critical phase transition temperature () of VO₂ (M) was adjusted by Nb and W co-doping. The of Nb-doped VO₂ (M) decreased at a rate of approximately 10 °C/at% Nb dopant, and the transition temperature could also be accurately controlled to room temperature (about 27 °C) by co-doping with Nb and W.

Toluene decomposition by DBD-type plasma combined with metal oxide catalysts supported on ferroelectric materials.

We investigated toluene decomposition with a single-stage plasma catalytic system operated at atmospheric pressure and working at reduced temperature (T < 75 degrees C), where a synergistic catalyst was integrated on ferroelectric BaTiO3 beads with a high dielectric constant. The catalyst species were characterized by FE-SEM and XPS before and after the experiment. The MnO2/BaTiO3 catalyst showed high stability in igniting plasma during destruction of toluene for 230 hours in a lifetime test.

Preparation of in-situ Pt nanoparticles into frameworks of mesoporous silica for improving thermal stability.

The Pt/sulfur-containing mesoporous silica (SMS) was obtained through in-situ co-condensation of TESPTS and TEOS in the presence of a triblock copolymer template. Strong interaction between the Pt NPs and S moieties of TESPTS in the SMS frameworks played an important role in the stabilization of Pt NPs against the sintering or coalescence problems. The Pt/SMS significantly improved the thermal stability at high temperature.

Influence of reaction parameters on size and shape of silica nanoparticles.

It was investigated that the effect of various synthesis parameters such as, types of silicon alkoxides and alcohols, ammonia (catalyst) concentration, and reaction temperature on the particle size and shape of silica nanosphere by Sol-Gel method. When different silicon alkoxides were used, the silica particles except tetramethylorthosilicate (TMOS), all were spherical, and after reaching a maximum, the sizes were decreased with carbon chain length due to its steric effect. As the alcohol chain length increased from methanol (MeOH) to n-butanol (BuOH), the average particle size was increased from 30 nm to 800 nm.