Defects in covalent organic frameworks (COFs) play a pivotal role in determining their properties and performance, significantly influencing interactions with adsorbates, guest molecules, and substrates as well as affecting charge carrier dynamics and light absorption characteristics. The present review focuses on the diverse array of techniques employed for characterizing and quantifying defects in COFs, addressing a critical need in the field of materials science. As will be discussed in this review, there are basically two types of defects referring either to missing organic moieties leaving free binding groups in the material or structural imperfections resulting in lower crystallinity, grain boundary defects, and incomplete stacking. The review summarizes an in-depth analysis of state-of-the-art characterization techniques, elucidating their specific strengths and limitations for each defect type. Key techniques examined in this review include powder X-ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), scanning tunneling microscope (STM), high resolution transmission electron microcoe (HRTEM), gas adsorption, acid–base titration, advanced electron microscopy methods, and computational calculations. We critically assess the capability of each technique to provide qualitative and quantitative information about COF defects, offering insights into their complementary nature and potential for synergistic use. The last section summarizes the main concepts of the review and provides perspectives for future development to overcome the existing challenges.

中文翻译：

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探测共价有机框架中的缺陷


共价有机框架 (COF) 中的缺陷在决定其性质和性能方面发挥着关键作用，显着影响与吸附物、客体分子和底物的相互作用，并影响载流子动力学和光吸收特性。本综述重点关注用于表征和量化 COF 缺陷的各种技术，以满足材料科学领域的关键需求。正如本综述将讨论的，基本上有两种类型的缺陷，要么是缺少有机部分，在材料中留下自由结合基团，要么是结构缺陷，导致结晶度较低、晶界缺陷和不完全堆叠。该评论总结了对最先进的表征技术的深入分析，阐明了每种缺陷类型的具体优势和局限性。本综述研究的关键技术包括粉末 X 射线衍射 (PXRD)、红外光谱 (IR)、热重分析 (TGA)、核磁共振 (NMR)、X 射线光电子能谱 (XPS)、扫描电子显微镜 (SEM) 、扫描透射电子显微镜（STEM）、扫描隧道显微镜（STM）、高分辨率透射电子显微镜（HRTEM）、气体吸附、酸碱滴定、先进电子显微镜方法和计算计算。我们严格评估每种技术提供有关 COF 缺陷的定性和定量信息的能力，深入了解它们的互补性质和协同使用的潜力。最后一部分总结了审查的主要概念，并为克服现有挑战的未来发展提供了前景。