State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, China.
Department of Chemistry, Xi'an Jiao Tong-Liverpool University, Suzhou, China.
Nat Commun. 2023 Apr 14;14(1):2133. doi: 10.1038/s41467-023-37296-0.
Two-dimensional covalent organic frameworks (2D COFs) are promising for gas sensing owing to the large surface area, abundant active sites, and their semiconducting nature. However, 2D COFs are usually produced in the form of insoluble micro-crystallites. Their poor contacts between grain boundaries severely suppress the conductivity, which are too low for chemresistive gas sensing. Here, we demonstrate that halide perovskites can be employed as electric glues to bond 2D COF crystallites to improve their conductivity by two orders of magnitude, activating them to detect NO with high selectivity and sensitivity. Resonant microcantilever, grand canonical Monte Carlo, density functional theory and sum-frequency generation analyses prove that 2D COFs can enrich and transfer electrons to NO molecules, leading to increased device conductivity. This work provides a facile approach for improving the conductivity of polycrystalline 2D COF films and may expand their applications in semiconductor devices, such as sensors, resistors, memristors and field-emission transistors.
二维共价有机框架（2D COFs）由于具有大的比表面积、丰富的活性位点和半导体性质，在气体传感方面具有很大的应用前景。然而，二维 COFs 通常以不溶性微晶的形式产生。晶界之间较差的接触严重抑制了导电性，对于化学电阻式气体传感来说，导电性太低。在这里，我们证明卤化物钙钛矿可以用作电胶，将二维 COF 微晶键合在一起，通过两个数量级提高其导电性，使它们能够高选择性和灵敏度地检测 NO。共振微悬臂梁、巨正则蒙特卡罗、密度泛函理论和和频产生分析证明，二维 COFs 可以使电子富集并转移到 NO 分子上，从而增加器件的导电性。这项工作为提高多晶二维 COF 薄膜的导电性提供了一种简便的方法，并可能扩展其在半导体器件中的应用，如传感器、电阻器、忆阻器和场发射晶体管。
