Carbon Nitrides: Metal-free Materials for Energy Applications

我们的项目旨在开发和优化一类新的无金属电活性石墨碳氮化物材料（gCNMs），作为锂离子电池（LIB）电极，超级电容器（SC）和燃料电池催化剂载体。这些都是重要的能源相关应用。gCNM基于sp2键合的碳和氮原子的层，类似于C-石墨或石墨烯，但它们在层内和层间含有空隙或通道，从而提供三维特征，我们将在这里开发用于可逆Li+嵌入和LIB应用。在由UCL Enterprise提供的为期12个月的奖励支持的概念验证研究期间，我们发现gCNMs的Li+存储容量可以与C-石墨竞争（专利申请1311742.9，提交日期：2013年1月7日）。在这个项目中，我们将应用一种系统的方法，结合合成化学，从头算理论预测，先进的表征和电化学测试，以控制和优化gCNM作为LIB电极材料的潜力。gCNM层由三嗪（C3 N3）或七嗪（C6 N7）单元通过-N=或-NH-基团连接而成。完全缩合的结构具有组成C3 N4：-NH-键的数量增加用于不完全聚合，并且这控制了层内和层之间的电子性质以及空隙和通道。非键合电子对和连接到氮的可交换H原子为无金属超级电容器提供电荷存储能力。我们项目的第二个领域将优化用于SC应用的gCNMs。我们将系统地调整合成和加工，以控制层冷凝和空隙排列，为每个应用优化。我们将使用模板来生产具有受控孔隙率的分层结构，并将材料纳入电化学测试设备中。我们还将建立在我们的观察，gCNMs显示出作为燃料电池应用的催化剂载体材料的前景。我们将优化微结构、表面化学和电子特性，生产出一系列坚固高效的新型支撑材料，这些材料在数百次循环中保持稳定。我们的项目结合了化学和化学工程方法，从而设计和建造演示设备。我们将与工业合作伙伴合作，在实际操作条件下测试和优化材料和设备，以提供快速商业化的途径。我们的gCNMs在物理和化学上与当前使用的C基材料兼容，因此与当今技术兼容。然而，由于其上级性能，它们将代表在应用潜力方面向前迈出的重要一步。我们的项目旨在确保研究的预测-合成-测试组成部分之间不断反馈，以便有效和明智地识别和优化每个应用的关键材料和性能目标。我们的研究团队处于gCNMs合成，表征和电化学测试的最前沿，他们已经申请了第一个结果的专利，该结果显示出比C-石墨作为LIB电极材料具有上级性能。他们还观察到gCNMs作为甲醇氧化燃料电池的Pt催化剂载体材料的优异稳定性，并预测其作为无金属超级电容器的作用。我们希望利用这一独特的机会，在开发用于电化学应用的gCNMs这一新领域建立英国领先地位。PI在几个项目上密切合作，这些项目将基础科学与应用科学相结合，并参与能源相关应用的产品和设备的商业化。

Our project aims to develop and optimise a new class of metal-free electroactive graphitic carbon nitride materials (gCNMs) as lithium ion battery (LIB) electrodes, supercapacitors (SC) and fuel cell catalyst supports. These are important energy-related applications. gCNMs are based on layers of sp2-bonded carbon and nitrogen atoms similar to C-graphite or graphene, but they contain voids or channels within and between the layers giving a 3-dimensional character that we will develop here for reversible Li+ intercalation and LIB applications. During proof-of-concept studies supported by a 12-month award from UCL Enterprise we found that the Li+ storage capacity of gCNMs could be competitive with C-graphite (patent application 1311742.9, filed 1/7/13). In this project we will apply a systematic approach combining synthetic chemistry, ab initio theoretical prediction, advanced characterisation and electrochemical testing to control and optimise the potential of gCNMs as LIB electrode materials.The gCNM layers are built from triazine (C3N3) or heptazine (C6N7) units linked by -N= or -NH- groups. Fully condensed structures have composition C3N4: the number of -NH- linkages increases for incomplete polymerisation and this controls the electronic properties as well as voids and channels within and between layers. Non-bonded electron pairs and exchangeable H atoms attached to nitrogen provide charge storage capabilities for metal-free supercapacitors. A second area of our project will optimise gCNMs for SC applications.We will systematically tune the synthesis and processing to control the layer condensation and void arrangements optimised for each application. We will use templates to produce hierarchical structures with controlled porosity and incorporate the materials in electrochemical test devices. We will also build on our observation that gCNMs show promise as catalyst support materials for fuel cell applications. We will optimise the microstructure, surface chemistry and electronic properties to produce a new family of robust and efficient support materials that remain stable over many hundreds of cycles.Our project combines chemistry and chemical engineering approaches leading to design and construction of demonstrator devices. We will work with industrial partners to test and optimise the materials and devices under realistic operating conditions to provide a rapid route to commercialisation. Our gCNMs are physically and chemically compatible with C-based materials in current use and so are compatible with present-day technology. However because of their superior performance they will represent a major step forward in terms of application potential. Our project is designed so that there is constant feedback between prediction-synthesis-testing components of the research to permit efficient and informed identification and optimisation of key materials and properties targets for each application.Our team of researchers is at the forefront of synthesis, characterisation and electrochemical testing of gCNMs and they have patented the first result showing superior performance over C-graphite as LIB electrode materials. They have also observed excellent stability of gCNMs as Pt catalyst support materials for methanol oxidation fuel cells and predicted their action as metal-free supercapacitors. We wish to take advantage of this unique opportunity to build the UK lead in this new area of developing gCNMs for electrochemical applications. The PIs work closely together on several projects that integrate fundamental to applied science and are involved in commercialising products and devices for energy-related applications.