Surface Integrity and Carbon Chemical Vapor Deposition on Nickel Foil: Surface Abrasive Treatment

Carbon chemical vapor deposition on bulk nickel surfaces generated by abrasive treatment was experimentally studied. Initial stages of deposition were closely examined to elucidate possible effect on the formation and properties of carbon nanotube layers grown directly on bulk metal substrates. Two main phenomena complicate graphite-like carbon deposition on rough nickel surface in comparison with the perfect one. The first phenomenon is the rate increase of carbon formation at surface defects including small confined spaces with large surface-to-volume ratio (pits, gaps, cracks, etc.). Small cavities in subsurface layer are also places of enhanced carbon formation. The cause of this increase is the specific chemistry of hydrocarbon pyrolysis in the conditions of prolonged residence time realized in confined space. The high rate of carbon formation leads to fast growth of highly disordered (coke-like) graphite carbon inside such defects. The second phenomenon is the fast metal dusting of micron-sized surface asperities formed by plastically deformed metal and generated by abrasive treatment. Numerous micro-cracks created on surface in course of metal dusting promote the first phenomenon becomes operative. It was proposed that the roughness of catalytically active surface can be the cause of pyrolysis surface chemistry change comparing with smooth surface. (C) 2015 The Electrochemical Society. All rights reserved.