Graphene coated Ni films: A protective coating

The requirement of protective coating to prevent refined metals from reactive environments is very important in industrial and academic applications. Most of the conventional methods used for this purpose introduce several negative effects including increased thickness and changes in the optical, electrical and thermal properties of the metal. In this paper, we demonstrate the coating of graphene films grown by chemical vapor deposition to protect the surface of Ni substrates from air oxidation. In particular, graphene prevents the formation of oxide on the metal surface and protect it from reactive environment. Two methods are adopted to induce oxidation on the graphene coated Ni surface: firstly by heating the specimen in air for several hours and secondly, by immerging into a solution of 31% hydrogen peroxide (H2O2). The specimens have been characterized by X-ray diffraction, Optical micrograph, Raman spectroscopy, X-ray photoelectron spectroscopy and the results indicate that the surface is well protected from the oxidation even after heating the specimen upto max. temperature of 500 degrees C in air for 3 h. It is also observed that graphene provides effective resistance against H2O2. The detailed analysis of graphene as oxidation resistance against air and H2O2 has been presented. (C) 2012 Elsevier B.V. All rights reserved.