Graphene Electrochemistry: Understanding fundamental electron transfer at graphite electrodes

Electrochemistry is concerned with the transfer of charge between a solid (the electrode) and a molecule, which is usually in solution. The properties of the electrode itself may be important, particularly in the case of carbon surfaces, which is especially relevant in view of their widespread applications as electrode materials. Graphitic forms of carbon are plentiful, non-toxic and highly conductive, and have thus found uses as disposable electrode materials in electrochemical glucose sensing, or as continually-used substrates in energy storage and generation (e.g. lithium ion batteries, super-capacitors and fuel cells). In each of these roles, the interfacial properties, and particularly the charge transfer kinetics, of the carbon are essential. Such commercial electrochemical applications of carbon have traditionally used screen-printed or activated carbons, formed from micron-scale amorphous or graphitic particles, often mixed with a polymeric binder. There has been enormous interest in the last decade or so in the use of nano-scale carbon materials, both from the viewpoint of fundamental understanding of their properties and their technological exploitation. Carbon nanotubes (CNTs) consist of rolled up 1-dimensional sheets of carbon atoms. Recently 2-dimensional carbon in the form of single graphite sheets, known as graphene, has been isolated. These analogues of graphite have attracted much interest because of their unique electronic properties, not least the exceptionally high carrier mobility, and atomically well-defined structure. These properties have stimulated enormous interest in theoretical and experimental studies of charge TRANSPORT within CNTs and graphene. An equally interesting area, given the myriad of electrochemical applications of carbon (see above) is to understand the case of interfacial charge TRANSFER from the low dimensional carbon to a redox-active molecule. In particular, the structure of mono- and bi-layer graphene provides an ideal model system with which fundamental questions about charge transfer to/from carbons can be answered. The approach we will pursue exploits the lead position held by the UK generally, and Manchester in particular, established by the experimental isolation of high purity graphene by Novoselov et al in 2004 . We will use graphene samples defined by lithographically etched windows to study the interfacial charge transfer characteristics of the material as a function of structure. Experimental work will be supported with state-of-the-art computation.

BENEFICIARIES: UK Industry: We have developed contacts with the UK research laboratory of Morgan Electrical Carbon Ltd (see letter of support, detailing the staff time and equipment they will make available for this project), who have identified an internal shortage of expertise in the area defined by the proposal - which therefore compliments their existing R and D activity. Wider Society: Given the growing importance of future alternative energy vectors, improved understanding (from both a fundamental and an applied perspective) of potential low carbon energy sources will be a critical issue for all developed economies. The applicants have a number of links with the energy industry/relevant public bodies (see Impact statement for details). HOW WILL THE ABOVE BENEFIT: Morgan Electrical Carbon Ltd will benefit from the latest up-to-date research and would be able to use the research staff trained through the project as a source of new employees. More specifically, there is considerable scope for the development of intellectual property (IP) during this project. Wider Society: Carbon based materials are essential to a variety of technologies which are reliant on electrochemistry (notably in the areas of energy storage/transfer and amperometric detection) - fundamental improvements in the understanding/performance of such materials will have significant wider impact, economic and beyond. TRANSFER OF KNOWLEDGE TO THE ABOVE: The applicants have a good track record of publicising research/engaging the wider public, specifically through Partnership in Public Engagement grants, meeting organisation, schools outreach work and protection of appropriate intellectual property. Details are given in the impact statement. Regular meetings will be held with Morgan, as the identified industrial partner, to ensure rapid exploitation of intellectual property generated by the project. .