Selective intercalation and diffusion processes in crystalline carbon nitride nanostructures

石墨碳氮化物（gCN）是一类基于交替的sp2键C和N原子的低维层状化合物;它们可以被剥离成与石墨烯类似的几个原子层厚的纳米结构，但是具有衍生自允许可调带隙的杂芳族化学的化学官能团的额外益处，嵌入化学及其在催化和能源关键领域的应用。该项目的目标是开发和应用精确的电子结构计算技术来研究碳的结构化学。氮化物材料，以及它如何与所需性质相关，包括：-表面终止和暴露的N原子的酸/碱特征的控制; -通过嵌入化学的带隙调谐和光催化性质的控制; -客体原子/离子/分子在氮化碳框架中的嵌入和扩散的机制;-表面与溶剂分子的相互作用，从而了解可能的剥离机制。该项目将广泛使用基于密度泛函的量子化学计算方法。理论和能量最小化技术。将通过沿沿着选定的反应坐标对系统能量进行采样，如移动的物质的质心位移，对机制研究进行过渡态搜索。适当时，从头算分子动力学（AIMD）计算也将用于检查层内和层间插层剂的流动性。本研究的另一个目标是探索AIMD模拟结果如何用于比较和合理化使用准弹性中子散射（QENS）技术的实验测量。合理理解氮化碳材料的结构-性能关系对于优化现有性能以及设计用于特定能源相关应用的下一代化合物至关重要。该项目与EPSRC物理科学主题中的几个研究领域保持一致，包括能源应用材料（生长），化学反应动力学（维持）和凝聚态物质，电子结构（维持），前者（能源应用材料）提供了最接近的匹配。

Graphitic carbon nitrides (gCN) are a family of low dimensional layered compounds based on alternating sp2-bonded C and N atoms; they can be exfoliated into few atomic layer thick nanostructures analogue to graphene, but with the additional benefit of chemical functionality derived from the heteroaromatic chemistry that allows tunable band gap, intercalation chemistry and applications in critical areas of catalysis and energy.The goal of this project is to develop and apply accurate electronic structure computational techniques to study the structural chemistry of the carbon nitride materials, and how it correlates with desired properties, including:- surface termination and control of the acid/base features of the N atoms exposed; - band gap tuneability through intercalation chemistry and control of the photocatalytic properties; - mechanism for intercalation and diffusion of guest atoms/ions/molecules in the carbon nitride framework; - surface interaction with solvent molecules leading to understanding of possible exfoliation mechanisms.The project will make extensive use of quantum chemical computational methods based on Density Functional Theory and energy minimisation techniques. Transition state searches for mechanistic studies will be applied through sampling the system energy along chosen reaction coordinates, such as the displacement of the centre of mass for mobile species. When appropriate, ab initio molecular dynamics (AIMD) calculations will also be employed to examine the mobility of intercalants within and between the layers. An additional goal of this reasearch will be to explore how results from AIMD simulations can be used to compare and rationalise experimental measurements using Quasi Elastic Neutron Scattering (QENS) techniques. Rational understanding of the structure-property correlation of the carbon nitride materials is critical for the optimisation of current properties, as well as the design of next generation compounds for specific energy related applications.The project aligns with several EPSRC research Areas within the Physical Sciences Theme, including those on Materials for energy applications (grow), Chemical reaction dynamics (maintain) and Condensed-matter, electronic structure (maintain), with the former (materials for energy application) providing the closest match.