Oxidation resistance of graphene-coated molybdenum: Effects of pre-washing and hydrogen flow rate

An effective approach to protect metal surfaces against oxidation and corrosion is of great importance for various practical and industrial applications. Current solutions, however, typically introduce several undesired effects, including increased thickness and changes in the metal's physical properties. Here, we demonstrate the formation of a graphene coating using an atmospheric pressure chemical vapor deposition (APCVD) technique combined with a specifically tuned hydrogen flow rate (200, 500, and 1000 sccm) and an acid solution for pre-washing. The pre-washing process consists of acid etching by three different acids that help to remove impurities. These impurities include native molybdenum oxide and impurities that can act as nucleation centers for multilayer graphene. The specimens were characterized by Raman spectroscopy, optical microscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Results indicate that the molybdenum surface was well protected from oxidation, even after heating to a temperature of 300 °C in air for 2 h.