Acetylene (C2H2) and copper foil have been chosen as carbon precursor and catalyst, respectively, for the synthesis of graphene by atmospheric pressure chemical vapor deposition. The effects of hydrogen (H2) concentration on graphene growth have been studied by Raman spectroscopy and transmission electron microscopy. Different to methane as a carbon precursor, high-quality bilayer graphene films can be grown rapidly with the ratio of H2 and argon (Ar) flow rates (H2/ Ar) range from 0.010 to 0.111. However, with the further increase of H2 concentration (H2/Ar = 0.250 and H2/Ar = 0.429), multilayer graphene domains are dominant on top of the bilayer graphene films. These observations demonstrate that H2 serves as an activator of the surface bound carbon for the bilayer graphene growth, while showing an etching effect that controls the morphology, nucleation density, and nucleation size of the multilayer graphene domains. The results offer useful insights into the understanding of the kinetic effect of H2 on scalable synthesis of graphene with C2H2.
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机译：乙炔（C2H2）和铜箔已分别被选作碳前体和催化剂，用于通过大气压化学气相沉积法合成石墨烯。氢（H2）浓度对石墨烯生长的影响已通过拉曼光谱和透射电子显微镜进行了研究。与作为碳前体的甲烷不同，高质量的双层石墨烯薄膜可以快速生长，氢气和氩气（Ar）的流量之比（H2 / Ar）为0.010至0.111。但是，随着H2浓度的进一步增加（H2 / Ar = 0.250和H2 / Ar = 0.429），多层石墨烯域在双层石墨烯薄膜的顶部占主导地位。这些观察结果表明，H 2用作双层石墨烯生长的表面结合的碳的活化剂，同时显示出控制多层石墨烯域的形态，成核密度和成核尺寸的蚀刻效果。结果为了解H2对可伸缩合成C2H2石墨烯的动力学效应提供了有用的见解。
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