▎ 摘　　要

Growth of defect-free large-area mixed mono-and bi-layer graphene using refined cooking palm oil on nickel (Ni) via thermal chemical vapor deposition was demonstrated for the first time. Small surface roughness of Ni substrate was obtained by annealing in hydrogen (H-2) ambient. Small surface roughness of Ni substrate and introduction of high H2 concentration during the growth improve the uniformity and suppress the formation of defect in the grown graphene. Coverage of mixed mono- and bi-layer graphene up to 65% was obtained. The grown graphene film showed an optical transmission of 80% at a wavelength of 550 nm, and a sheet resistance of 12.89 k Omega/sq. This work provides an alternative approach towards a development of less expensive growth technology using safe, easily obtained, low value raw carbon containing precursor. (C) 2016 Elsevier B.V. All rights reserved.