Graphene Electrochemistry: Understanding fundamental electron transfer at graphite electrodes

电化学与固体(电极)和分子之间的电荷转移有关，分子通常在溶液中。电极本身的性质可能很重要，特别是在碳表面的情况下，鉴于其作为电极材料的广泛应用，这一点尤其相关。碳的石墨化形式丰富、无毒、高导电性，因此被用作电化学葡萄糖传感的一次性电极材料，或作为能量储存和发电的连续使用的基质(例如锂离子电池、超级电容器和燃料电池)。在这些作用中，碳的界面性质，特别是电荷转移动力学是必不可少的。这种碳的商业电化学应用传统上使用丝网印刷或活性碳，由微米级的非晶态或石墨化颗粒形成，通常与聚合物粘结剂混合。在过去十年左右的时间里，人们对纳米级碳材料的使用产生了极大的兴趣，无论是从基本了解其性质的角度还是从技术开发的角度来看。碳纳米管(CNT)由卷起的一维碳原子片组成。最近，以单片石墨片的形式存在的二维碳被分离出来，也就是众所周知的石墨烯。这些石墨的类似物由于其独特的电子性质，尤其是极高的载流子迁移率和原子定义良好的结构，引起了人们的极大兴趣。这些性质激发了人们对碳纳米管和石墨烯中电荷传输的理论和实验研究的极大兴趣。考虑到碳的无数电化学应用(见上文)，一个同样有趣的领域是理解从低维碳到氧化还原活性分子的界面电荷转移的情况。特别是，单层和双层石墨烯的结构提供了一个理想的模型体系，可以用来回答关于碳的电荷转移的基本问题。我们将采用的方法利用了英国，特别是曼彻斯特的领先地位，这一地位是由Novoselov等人在2004年通过实验分离高纯度石墨烯而建立的。我们将使用由光刻刻蚀窗口定义的石墨烯样品来研究材料的界面电荷转移特性作为结构的函数。实验工作将得到最先进的计算支持。

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.