3D Cuprous Iodide Cluster‐Covalent Organic Framework for Ultrasensitive and Highly Selective Trace HF Detection at Room Temperature

ABSTRACT

Hydrofluoric acid (HF) poses a serious and irreversible threat to human health necessitating the development of highly sensitive and selective detection materials. Herein, a three‐dimensional cuprous iodide cluster‐based covalent organic framework (CuI‐MCOF), with diamond topology has been successfully prepared, which shows an ultrafast and highly sensitive response to HF gas. At room temperature, CuI‐MCOF displays an exceptional response of 7188% toward 100 ppm HF, with remarkably rapid response/recovery times of 3 s/2 s at 4 ppm. Notably, the sensor achieves an ultralow detection limit of 21 ppb, outperforming previously reported HF sensors. Moreover, it demonstrates outstanding selectivity and anti‐interference performance, maintaining stable responses to 4 ppm HF even in the presence of 16 interfering gases (100 ppm each). Experiments combined with density‐functional theory calculations reveal that the imine‐linker N atoms serve as reversible HF adsorption–desorption sites, while the electron‐rich CuI clusters enhance dipole interactions and facilitate charge transfer. Leveraging these properties, an on‐chip miniaturized perceptron system integrated with evaluation algorithms is developed for anti‐interference HF discrimination, spatiotemporal distribution estimation, and leakage source prediction. This work provides a new strategy for designing high‐performance HF sensors and expands the application of cluster‐based COFs in gas sensing.