Templated Synthesis of Graphene

Abstract

Producing cost effective graphene remains difficult and is a large barrier to the material realising its full potential. Current techniques are either very expensive to scale requiring high temperatures and low pressures, or produce a product not suitable for many of the big marquee applications in electronics. This document proposes developments on the chemical vapour deposition process of producing graphene by using high surface area templating material. This allows the synthesis of larger quantities of high quality graphene.

The added benefits of the methods proposed here is an increased control in the morphology of the produced graphene. Studies have shown that changes in morphology of graphene have a large effect on the properties and allow for different applications.

In this document, four templating material are used to grow graphene. Two use a powdered catalyst of cobalt hydroxide hexagons and copper oxide cubes and both successfully catalyse and template the synthesis of carbon. On the cobalt hexagons, depending on conditions, curved graphitic materials would arrange into a hexagonal macrostructure or high quality graphene would be produced with little evidence of hexagonal shape. On the copper oxide cubes, three clear products could be produced depending on the conditions. Carbon nanofibers would either arrange themselves into cubes or fibrous "worm" like structures. Also thin carbon coatings could be produced on the cube.

The other two method were the templating the graphene on a foam template in order to synthesise graphene foams. Graphene foams have numerous applications including energy storage, gas storage and supports. The first method describes synthesis of graphene on a metal foam templated from a hydrogel. Two products were synthesised depending on the conditions - firstly a high quality graphene/graphite foam was synthesised. Also a foam macrostructure of closed graphitic structures was produced. The second method produced graphite foams from poly high internal phase emulsion template.