Formation of nanoparticles and nanorods in a N2-C2H4-H2 atmospheric pressure dielectric barrier Townsend discharge

In the present publication, the effect of the addition of H2 in an atmospheric pressure Townsend Dielectric Barrier Discharge in an atmosphere of N2-C2H4 is examined with an emphasis put on the evaluation of the surface chemistry and growth mechanisms. Scanning Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron Spectroscopy and Fourier Transform Infrared Spectroscopy were used to characterize the coatings. For all H2 concentrations, films obtained present high N/C ratio (∼ 0.8) with high NHx and nitrile content. However, when H2 is added in the discharge, nanoparticles/nanorods are formed imbedded in a smooth film. The average size of the nanorods is 100-200 nm in diameter with length from 1 to 10 μm. A growth mechanism is proposed to explain the formation of the nanorods on the surface of the coating in the presence of H2.