Selective detection of phosgene by nanocrystalline diamond layer

Nanocrystalline diamond (NCD) films were grown on gold/Al(2)O(3) substrate using microwave plasma-enhanced chemical vapor deposition (PECVD) process. The NCD morphology was controlled by the deposition time and it was investigated by scanning electron microscopy (SEM). Gas sensing properties of NCD surface conductivity to humid air, CO(2), NH(3), and COCl(2) gases were measured by impedance measurements at room and at high temperature (140 degrees C). The H-terminated NCD surface shows a significant response to oxidizing gas (humid air, COCl(2)) in comparison to reducing gases (CO(2), NH(3)). (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim