Nanocrystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapor deposition （PECVD） at H2 and Ar atmosphere, using WF6 and CH4 as precursors. The crystal phase, st...Nanocrystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapor deposition （PECVD） at H2 and Ar atmosphere, using WF6 and CH4 as precursors. The crystal phase, structure and chemical components of the films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）, respectively. The results show that the film prepared at CH4/WF6 concentration ratio of 20 and at 800℃ is composed of spherical particles with a diameter of 20-35 nm. Electrochemical investigations show that the electrochemical real surface area of electrode of the film is large, and the electrode of the film exhibits higher electro-catalytic activity in the reaction of methanol oxidation. The designated constant current of the film catalyst is 123.6 mA/cm^2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 and 2.0 mol/L at 70℃, and the designated constant potential is only 0.306 V （vs SCE）.展开更多
基金This work was supported by the National Natural Scmnce Foundation of China(Grant Nos.20276069,20476097)
文摘Nanocrystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapor deposition （PECVD） at H2 and Ar atmosphere, using WF6 and CH4 as precursors. The crystal phase, structure and chemical components of the films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）, respectively. The results show that the film prepared at CH4/WF6 concentration ratio of 20 and at 800℃ is composed of spherical particles with a diameter of 20-35 nm. Electrochemical investigations show that the electrochemical real surface area of electrode of the film is large, and the electrode of the film exhibits higher electro-catalytic activity in the reaction of methanol oxidation. The designated constant current of the film catalyst is 123.6 mA/cm^2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 and 2.0 mol/L at 70℃, and the designated constant potential is only 0.306 V （vs SCE）.
