We have studied the influence of nitrogen on the chemical properties of the hydrogenated carbon nitride (a-CNx;:H) film deposited by CH 4/N2 dielectric barrier discharge (DBD) plasma. X-ray photoelectron spectroscopy (XPS) indicates that carbon and nitrogen form an unpolarized covalent bond in these C - Nx materials, and the observed chemical shift in the C Is and N Is binding energy is explained with respect to N Is incorporation. Furthermore, the average nitrogen content (N/C ≈ 0.76) in the films was systematically varied by changing the nitrogen partial pressure (CH4/N2 ≈ from 5:1 to 1:7) which is well supported by the elemental analysis. Fourier transform infrared (FTIR) absorption spectra exhibit significant changes in different C - N, C≡N, and NH/OH molecular bands at higher nitrogen concentration in the film. The isonitrile and nitrile groups ( - NC and - CN) are increased with the increase of deposition time. In addition, the elemental analysis, proton NMR, and thermolysis mass spectrum show that the composition of the film with the ratio CH4N2 ≈ 1:1 is C, 67.68; H, 9.88; N, 16.53 (in wt %) and that the film is composed of polymers, probably containing linear chains which are cleaved off on heating in vacuum.
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Physical and Theoretical Chemistry
- Materials Chemistry