凯发

Graphene, a hexagonal network consisting of a single layeror few layers of carbon atoms, has attracted great attentionbecause of its unique optical, electronic, mechanical, and thermal properties.[1-4] Other outstanding properties of graphene include its high strength, ductility and remarkable chemical inertness unless exposed to harsh reaction conditions.[5] Chemical vapor deposition (CVD) techniques have been successfully applied to grow high quality single layer and multilayer graphene onto various metal substrates to obtain good resistance to corrosion.[6-9] Delaminated graphene coating can also achieve the same resistance to corrosion theoretically which many advantages, such as low cost, simple operation and low equipment requirement. The motivation for this work is based on the ability of graphene nanosheets coating to prevent diffusion of oxidizing gas and corrosive liquid solutions, which is expected to arrest the oxidation and increase the service life significantly without affecting the physical properties of the active metal copper as graphene nanosheets form atomically thin protective coating.

In this report, we present a simple method to realize graphene coating on metal substrates with good resistance to corrosion. Graphene nanosheets was prepared by supercritical CO2 assisted with ultrasound.[10,11] Metal substrates were immersed into graphene-alcohol dispersion liquid, and graphene coating was plated by electrophoretic deposition and dying for several times. The characterization results by optical microscope, contact angle, SEM and EDS demonstrate that graphene nanosheets coat the metal substrates evenly and completely, as shown in Fig. 1 and Fig. 2. Chemical and electrochemical investigations were performed to evaluate the corrosion resistance property of coatings.by tailoring graphene coating the chemical and electrochemical degradation of the metal substrates metal can be arrested significantly. The corrosion rate is 5-10 times reduced compared to metal substrates.

References:

[1] K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S.V. Dubonos, I.V.Grigorieva, A.A. Firsov, Science 306 (2004) 666–669.

[2] K.S. Novoselov, D. Jiang, F. Schedin, T.J. Booth, V.V. Khotkevich, S.V. Moro-zov, A.K. Geim, Proceedings of the NationalAcademy of Sciences of the United States of America 102 (2005) 10451–10453.

[3] K.S. Novoselov, A.K. Geim, Nature Materials 6 (2007)183–197.

[4] C.G. Lee, X.D. Wei, J.W. Kysar, J. Hone, Science 321 (2008) 385–390.

[5] Raman RKS, Banerjee PC, Lobo DE, Gullapalli H, Sumandasa M, Kumar A, et al. Carbon 2012;50:4040–5.

[6] Kirkland, N. T.; Schiller, T.; Medhekar, N.; Birbilis, N. Sci. 2012, 56, 1–4.

[7] Prasai, D.; Tuberquia, J. C.; Harl, R. R.; Jennings, G. K.; Bolotin, K. I. 2012, 6, 1102–1108.

[8] Singh Raman, R. K.; Chakraborty Banerjee, P.; Lobo, D. E.; Gullapalli, H.; Sumandasa, M.; Kumar, A.; Choudhary, L.; Tkacz, R.; Ajayan, P. M.; Majumder, M. Carbon 2012, 50, 4040–4045.

[9] Ambrosi, A.; Bonanni, A.; Sofer, Z.; Pumera, M. Nanoscale 2013, 2379–2387.