Electronic Conductive Metal-Organic Frameworks (EC-MOFs) materials are a new class of conductive porous crystalline materials formed by self-assembly of metal ions or metal ion clusters and organic ligands through coordination bonds. A class of crystalline materials that combine porosity, selectivity, and semiconductor properties. Due to its rich design of crystal structure and adjustable electronic band structure, EC-MOFs materials are used as active functional components in the field of semiconductor field devices such as novel field effect transistors, lithium batteries, supercapacitors, and gas sensors. Has high research value and application potential. However, the application of reported EC-MOFs materials is mostly in the form of powder or thick film, and the large particle size and grain boundaries limit the transport of electrons and substances in electrical devices. It is well known that the quality of a film is one of the important determinants of a high performance device. The layer-by-layer (LbL) liquid phase epitaxy method is an effective method for preparing a thickness-controlled, homogeneous homogeneous MOFs film. However, only some of the MOFs with special secondary building units (SBU) can be prepared by the LbL method. The controlled epitaxial growth of the LbL method applied to EC-MOFs conductive films has not been reported so far. Bang Vape,Bang Disposable Vape,Bang Vape Kit,Bang Vape Pod,Bang Bar Disposable Pod tsvape , https://www.tsecigarette.com
Under the support of the National Natural Science Foundation of China, the Research Equipment Development Project of the Chinese Academy of Sciences and the Key Science Project of the Chinese Academy of Sciences, the research team led by Xu Gang, a researcher at the State Key Laboratory of Structural Chemistry of the Institute of Physical Structures of the Chinese Academy of Sciences, is thin and controllable. Progress in research on durable EC-MOFs films and devices.
Yao Mingshui, assistant researcher of the research group, and Lu Xiaojing, a master student, used the LbL spray method to prepare EC-MOFs films with controlled thickness and mass at the nanometer scale. EC-MOFs film growth is based on a class of chemically stable hexagonal EC-MOFs material Cu3(HHTP)2 (HHTP=2,3,6,7,10,11-hexahydroxytriphenylene), which is in ab Cu-HHTP two-dimensional conductive structure is formed in the direction, and is stacked in a slightly slipped ABAB mode along the c-axis to form a honeycomb microporous structure. The room temperature conductivity of the film can reach 2 S·m−1. The Cu3(HHTP)2 film prepared by the method has a single layer thickness of ~2 nm, a surface roughness of <5 nm, and a good crystal orientation along the [001] direction perpendicular to the substrate direction. These advantages give it great potential for high-efficiency electrical devices. As an application example, Cu3(HHTP)2 films grown on sapphire substrates with prefabricated gold interdigitated electrodes are directly applied to room temperature chemical resistance gas sensors. The experimental results show that the thinner the film at room temperature, the better the gas diffusion and charge transport capability, and the stronger the gas detection ability. The 20nm thick Cu3(HHTP)2 film has the best performance, and the 100ppm room temperature resistance can reach 129%, and it shows good selectivity and long-term stability to ammonia gas (~90% response value after 96 days). The analysis shows that the p-type response is derived from the Fermi level increase caused by the reductive ammonia adsorption (n-type doping effect), the carrier concentration decreases, resulting in a decrease in current; the high selectivity is mainly derived from the ammonia and Cu sites. Strong interaction with ligands. At the same time, due to the smooth surface of the film, and the tight particles and orientation accumulation, the charge transfer and mass transfer ability are further improved, and the response value of the reported Cu3(HHTP)2 thick film sensor is increased by more than one order of magnitude.
The relevant results were published in "German Applied Chemistry" and selected as the cover of the current period. The research work has received attention and reports from academic platforms such as Confucius, Nanoman and Research.