Carbon nitride thin films and nanopowders produced by CO2 laser pyrolysis

Nanocrystalline CNx particles and thin films were produced in a flow reacto r system by the CO2 laser pyrolysis of sensitised NH3-N2O-C2H2 reactant gas mixtures. Depending an the substrate nature (silicon or quartz) the SEM an d TED analysis of the CNx thin films revealed specific nucleation and growt h morphologies of crystallites, resembling the beta-C3N4 phase, in the case of C3N4 nanopowder synthesis, the relative concentration of the sensitiser s (SF6/C2H4) was varied to,minimise SF6 decomposition. The majority of the data obtained from powder analysis (XRD, XPS, and ir transmission measureme nts) suggests the presence of CN bonded phases and the formation of alpha- and beta-C3N4 structures. (C) 1999 IoM Communications Ltd.