LASER PYROLYSIS OF CARBON-NITROGEN GAS-PHASE COMPOUNDS - AN ATTEMPTEDAPPROACH TO CARBON NITRIDE FORMATION

We describe the possibility to synthesize carbon nitride fine powder b y laser pyrolysis of acetylene/nitrous oxide/ammonia mixtures. The pow ders were produced in a flow reactor by varying the relative concentra tions of the sensitizers (SF6/C2H4). The kinetics of the reaction was monitored by IR spectrophotometry of the exhaust gases. The powder cry stallinity and bond structure was studied by X-ray diffraction (XRD) a nd IR transmission spectrometry, respectively.The majority of XRD data suggests the presence of the predicted alpha- and beta-C3N4 structure s, with a concentration depending on starting conditions. The presence of C-N bonded phases seems relevant. Under the present conditions, th e slight contamination of powders by SF6 decomposition products could not be avoided. (C) 1998 Elsevier Science Ltd. All rights reserved.