Graphene oxide chemical synthesis

Figure 5.7 Schematic illustration of Brodie s method, Staudenmaier s method and Hummers method for the synthesis of graphene oxide hy chemical oxidation techniques.

A number of methods have been developed for the synthesis of the Au NPs on the graphene oxide (GO)/rGO nanosheets such as chemical reduction, electrochemical deposition, photo-assisted reduction, sonochemical methods, and microwave irradiation [19-24]. 

S. Stankovich, D.A. Dikin, R.D. Piner, K. a. Kohlhaas, A. Kleinhammes, Y. Jia, et al., Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide, Carbon,... 

The highlighted examples of gas phase hybridization clearly show that they are well suited for the deposition of metals and metal oxides. They are most practical when the nanocarbons are either surface bound or grown from a surface, such as CVD grown graphene and CNT forests. Improved control of layer thickness can be obtained, in comparison to wet chemical approaches, but the synthesis strategies generally require sophisticated equipment not often present in a laboratory. 

Since 2004 [183], graphene research has evolved from a heavily theoretical and fundamental field into a variety of research areas [301]. Its electrical, magnetic, physical-mechanical, and chemical properties position it as the most promising material for molecular electronic and optoelectronic applications, possibly replacing the currently used silicon and metal oxide based devices. Nonetheless, further research is essential in order to control easily such properties and construct devices with specific and novel architectures to explore in depth all of these exciting properties, as well as to achieve the synthesis of large-scale, size- and layer-count controlled graphene. 

For the third process, conducting polymers and metal oxides can be simultaneously deposited onto carbonaceous scaffolds by using CNTs or graphene as frameworks during chemical process or electrodes in the electrochemical procedure. This is similar to the one-pot synthesis of binary composites. Besides sequential compositing, ternary composites can also be fabricated by a one-step electrochemiccd deposition to reach desirable porous architectures due to its simplicity and reliability. It was proposed to prepare unique PPy/reduced GO/CNT ternary composites, where reduced GO, CNT, and PPy were electro-deposited simultaneously to construct a three-dimensionally highly porous film electrode (Dingetal., 2012). 

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