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 ...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）.展开更多
文摘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）.
