Uncovering the Electroactivity of Novel sp2 Carbon Materials through Quantitative High Resolution Visualisation

电化学是21世纪世纪的关键使能科学，支持重要的主题和技术，如能量（转换和存储），催化/电催化和传感（化学和生物化学）。所有这些应用都需要新的电极材料，这些材料可以超越现有技术并提供环境效益。在这种情况下，碳是非常有吸引力的：虽然（贵）金属必须开采和加工（能源成本高），但碳材料可以快速，廉价和有效地从含碳气体中生长出来。最近出现的新形式的碳，特别是石墨烯（蜂窝状排列的sp2碳原子的一个原子厚的平面片）和单壁碳纳米管（SWNT），其可以被视为石墨烯卷成纳米（十亿分之一米）尺度的直径的管，为电化学提供了令人兴奋的机会。单壁碳纳米管在电化学（电流传感）检测方面表现出惊人的性能，预计石墨烯将为电分析和电催化提供更好的前景。这两种材料构成了特别有趣的催化剂（金属，半导体，酶，细胞等）组装平台。并且可以用作太阳能电池中的透明电极。这些应用和许多其他应用需要了解碳电极和溶液中分子之间的电荷转移（电流）的基本方面。这是一个重大的实验挑战。sp2碳材料虽然具有长程有序性，（石墨烯、石墨和单壁碳纳米管）具有表面特征（缺陷和/或步骤）;在多大程度上，这些，而不是基底表面，有助于整体活动是一个主要的悬而未决的问题和相当大的辩论和重要性的问题。这一建议将承担的挑战，阐明，第一次，sp2碳材料的真实活性通过有史以来最高空间分辨率的电化学成像技术的开发和应用。这些技术将能够在迄今为止还不可能的尺度上测量跨表面的电化学活性。该技术基于“扫描探针”的概念，其中纳米尺度探针在表面上移动;在这种情况下，它将通过使用互补的显微镜方法测量微小细节的电化学活性，并将其与底层表面特性（结构和电学）联系起来。我们期望获得相关sp2碳材料活性起源的确切证据，并确定电荷转移是否仅在缺陷处驱动。将这一问题应用于广泛的重要电化学过程对该领域的发展至关重要，并将揭示sp2碳基电化学技术未来发展的最佳策略。围绕固体电极上活性位点的不确定性是普遍存在的，具有普遍性，我们完全期望所提出的技术在电化学和材料科学中得到广泛应用，人们试图了解表面反应性。该技术的下游应用可能包括了解腐蚀和支持燃料电池催化剂。最终，这些技术可以在生命科学中找到相当大的用途，包括探测生命系统和细胞器，在那里人们将能够在一分钟的尺度上测量化学通量。因此，这一建议对于新材料的基本理解以及更广泛的电化学和表面反应性具有根本的重要性。它将导致传感和电化学转换的新方法，并将为科学家提供具有深远多学科影响的新型高分辨率技术。

Electrochemistry is a key enabling science of the 21st century, underpinning important topics and technologies such as energy (conversion and storage), catalysis/electrocatalysis, and sensing (chemical and biochemical). All of these applications demand new electrode materials which can outperform existing technologies and offer environmental benefits. In this context, carbon is very attractive: while (precious) metals have to be mined and processed (with high energy costs), carbon materials can be grown from carbon-containing gases quickly, cheaply and efficiently. The recent emergence of new forms of carbon, in particular, graphene (a one-atom-thick planar sheet of sp2 carbon atoms in a honeycomb arrangement) and single-walled carbon nanotubes (SWNTs), which may be viewed as graphene rolled into tubes with a diameter on the nanometer (one-billionth of a meter) scale, presents an exciting opportunity for electrochemistry. SWNTs have displayed astonishing properties for electrochemical (current-sensing) detection, and it is anticipated that graphene will offer even better prospects for electroanalysis and electrocatalysis. Both materials constitute particularly interesting platforms for the assembly of catalysts (metal, semiconductor, enzymes, cells, etc.) and could find application as transparent electrodes in solar cells. These applications, and many others, require that the fundamental aspects of charge transfer (current flow) between carbon electrodes and molecules in solution is understood. This poses a major experimental challenge. While having long-range order, sp2 carbon materials (graphene, graphite and SWNTs) possess surface features (defects and/or steps); the extent to which these, rather than the basal surface, contribute to the overall activity is a major open question and a matter of considerable debate and importance.This proposal will take on the challenge of elucidating, for the first time, the true activity of sp2 carbon materials through the development and application of the highest spatial-resolution electrochemical imaging techniques ever. These techniques will be able to measure electrochemical activity across a surface on a scale which has not been possible hitherto. The techniques are based on the 'scanned probe' concept in which a nanoscale-probe is moved across a surface; in this case, it will measure the electrochemical activity in minute detail and relate it to the underlying surface properties (structural and electrical), via the use of complementary microscopy methods. We expect to obtain definitive proof of the origin of the activity of related sp2 carbon materials and to determine whether charge transfer is driven only at defects. Answering this question for a wide range of important electrochemical processes is vital for the advancement of the field and will reveal the best strategies for the future development of sp2 carbon-based electrochemical technologies.The uncertainty surrounding the active sites on solid electrodes is widespread and of a general nature, and we fully expect the techniques proposed to be applied extensively in electrochemistry and materials science, where one seeks to understand surface reactivity. Downstream applications of the techniques could include understanding corrosion and supported fuel cell catalysts. Ultimately, the techniques could find considerable use in the life sciences, including probing living systems and organelles, where one would be able to measure chemical fluxes on a minute scale. This proposal is therefore of fundamental importance to the basic understanding of new materials, as well as more broadly to electrochemistry and surface reactivity. It will lead to new methods of sensing and electrochemical transformations, and will provide scientists with novel high resolution techniques with far-reaching multidisciplinary impact.