Conducting two dimensional metal organic frameworks

本计画的目的是发展超高真空合成二维金属有机骨架材料的方法，以应用于气敏元件。传感技术将很容易实现，并提供对气相化学品的轻型移动的或网络化分子检测。传感器将廉价、轻便，并且不需要太多电力。最终，这样的气体传感器可以结合到移动的设备中，以提供对有害健康的气体的持续监测。主要项目重点是在表面上合成2D导电金属有机框架（MOFs），并使用扫描隧道显微镜（STM）和X射线光电子能谱对其进行表征。导电二维多金属纤维网络是近年来发现的一种新材料，它是由后过渡金属和一些简单的多环芳烃配体通过平面正方形配位而形成的。MOFs也将生长在绝缘衬底上，用于高灵敏度气体传感。然后可以在膜结构的质量与其用于挥发性有机化合物的化学电阻感测之间绘制相关性。该项目福尔斯属于EPSRC物理科学研究领域，其目标是：-在超高真空环境中生长二维MOFs，并使用扫描隧道显微镜、X射线光电子能谱、电导率测量、X射线衍射和拉曼光谱对所得材料进行表征。-使用高分辨率STM图像来区分混合金属MOF中的金属络合物中心，例如区分Ni和Co金属中心。通过在用叉指型贵金属电极装饰的电绝缘基底上沉积亚单层来创建2D MOF逾渗网络，并通过直流电阻和锁定技术来评估这些。- 将渗滤网络用于挥发性有机化合物（如C3 H8）和常见有害气体（包括CO和NH3）的气相传感。这将包括确定网络的检测极限。

The aim of the work in this project is to develop ultra high vacuum synthesis routes for two dimensional metal organic framework materials used in gas sensing. The sensing technology will be easily miniaturised and provide lightweight mobile or networked molecular detection of chemicals in the vapour phase. The sensors will be cheap, light, and not require much power. Ultimately such gas sensors could be incorporated into mobile devices to provide constant monitoring of gasses hazardous to health. The main project focus is to synthesise on a surface 2D conducting metal organic frameworks (MOFs) and characterise them using scanning tunnelling microscopy (STM) and X-ray photoelectron spectroscopy. Conductive 2D MOF networks are recently discovered materials, resulting from square planar complexation of late transition metals and some simple polyaromatic hydrocarbon ligands. The MOFs will also be grown on insulating substrates and used for high sensitivity gas sensing. A correlation can then be drawn between the quality of the film structure with its use for chemiresistive sensing of volatile organic compounds. If grown as percolation networks, then the MOF sensors will provide orders of magnitude increased sensitivity relative to thin film sensors made from the same materials.This project falls within the EPSRC Physical Sciences research area.The aims are:- To grow 2D MOFs in an ultra-high vacuum environment and to characterise the resultant materials using scanning tunnelling microscopy, X-ray photoelectron spectroscopy, electrical conductivity measurements, X-ray diffraction, and Raman spectroscopy.- To use high resolution STM images to distinguish between the metal complex centres in mixed-metal MOFs, for example to distinguish between Ni and Co metal centres.- To create 2D MOF percolation networks by depositing sub-monolayers on electrically insulating substrates decorated with interdigitated noble metal electrodes, and to evaluate these through dc resistance and lock-in techniques. - To use the percolation networks for gas phase sensing of volatile organic compounds such as C3H8 and common hazardous gasses including CO and NH3. This will include establishing the limit of detection of the networks.