Nano-crystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapour deposition in H2 and Ar atmosphere, using WF 6 and CH4 as precursors.The crystal phase, structure and chemical components of the films were characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）,respectively.The results showed that the film prepared at CH4/WF6 concentration ratio of 20,working pressure of 100Pa and temperature of 800℃ were composed of sphere particles with a diameter of 20—35 nm Electrochemical investigations show that the electrochemical surface area of electrode of the film was large.The electrode of the film exhibited higher electro-catalytic activity in the reaction of methanol oxidation,and its catalytic properties were similar to those of Pt or Pt group catalysts.The constant current of the film catalyst was 123.6 mA·cm -2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 mol·L -1 and 2.0 mol·L -1 respectively at 70 ℃, and its constant potential was only 0.306 V（ vs .SCE）.
Titanium dioxide (TiO2) nanoparticles of rutile phase were synthesized by hydrolysis of TiCl4 at 95 ℃ in aqueous solution. The samples as prepared and calcined at 500 ℃ were characterized by XRD, TG-DTA and TEM. The sample as prepared was of imperfect rutile structure, and its morphology was rod-like with a diameter of 10～20 nm, a length of 20～80 nm and an aspect ratio of 2～4. The structure of the sample calcined at 500 ℃ was a perfect rutile one, and its morphology was rod-like with a diameter of 15～25 nm, a length of 25～105 nm and an aspect ratio of 2～4. These results indicate that calcination temperature has a positive effect on the structure and the size of rutile nanocrystals, and has no effect on the aspect ratio of rutile nanocrystal. A model for the formation mechnism of rutile nanocrystal in aqueous solution under hydrolysis conditions has been proposed.
