Answer
Graphene:
Graphene is a semimetal with small overlap between the valence and the conduction bands. It is an allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice (figure 1).It is the basic structural element of many other allotropes of carbon, such as graphite, diamond, charcoal, carbon nanotubes and fullerenes.
Graphene Carbon along metal:
Metal oxides such as TiO2 and ZnO are large-band-gap semiconductors, and they are photocatalytically active under UV irradiation. These oxides are capable of interacting with graphene oxide via carboxylic acid functional groups. Thus, mixing of two suspensions of GO and TiO2 or ZnO results in the binding of oxide particles to graphene oxide
flakes. These particles remain suspended in suspension, minimizing any aggregation effects.
Graphene Oxide-Metal Nanoparticle Composites
Reduced graphene oxide serves as a support material to stabilize metal nanoparticles. For example, the synthesis of silver and gold nanoparticles stabilized by graphene oxide sheets has been reported by several research groups.These composites have also been assembled as ultrathin films using a layer-by-layer self-assembly technique.30 The procedure to make these composites consists of mixing of GO and a metal salt solution (AgNO3, HAuCl4, or H2PtCl6) and adding a dilute borohydride solution. The chemical reduction process reduces both GO and metal ions. The RGO acts as a support to stabilize metal nanoparticles.
Applications:
The resulting G-carbon composite exhibited competitive catalytic activity and superior methanol tolerance compared to a commercial Pt/C catalyst. Furthermore, it demonstrated significantly higher catalytic efficiency than a Pt/C catalyst.
