Synthesis of carbon nanomaterials by catalytic chemical vapor depositiongrowth mechanisms on metal powders and foils

Zusammenfassung

Carbon nanomaterials such as carbon nanotubes (CNTs) or monolayer graphene are proposed for a wide variety of theoretical applications due to the superior properties provided at the nanoscale. They can be produced by chemical vapor deposition (CVD), which consists on the thermal decomposition of hydrocarbons over metal catalysts. Highly ordered structures like CNTs arrays and fibres as well as large-area monolayer graphene films can be grown in a highly controlled manner at laboratory scale by selecting the proper CVD conditions, the metal catalyst composition and morphology. However, the highly controlled catalysts needed for their synthesis are currently produced by expensive techniques which are hard to scale. Alternatively, the use of commercially available bulk metal catalysts like powders, foils and meshes are shown to be a fast and low cost approach for the production of carbon nanomaterials with several morphologies and crystallinities. This alternative is already demonstrated in the literature, however most of the experimental work on synthesis on bulk metals focuses on the carbon produced, and there is a need of experimental work focused on growth mechanisms of carbon nanomaterials on these metal catalysts. We used nickel-based powders and stainless steel and copper foils for the production of carbon fibres, nanofibres, CNTs arrays and thin films by CVD, providing supported explanations on the carbon nanostructure growth mechanisms. Highly scalable processing developments in the production of graphene-based composite thin films are also presented, which expand the available portfolio of nanostructured carbon materials with potential applications in multifunctional surfaces.