Humidity Induced Proton–Electron Conducting Metal–Organic Frameworks of M<sub>3</sub>(Hexaiminobenzene)<sub>2</sub> (M = Ni, Cu, Fe) for Highly Sensitivity Drug Precursor Chemicals Gases Detection
Yiling Tan, Le Chen, Minglang Zhang, Bingsheng Du, Chengyao Liang, Xuezheng Guo, Liwen Yang, Shili Zhao, Yuanting Yu, Chun Huang, Hangyu Liu, Wenwen Liu, Linggao Zeng, Peng Zhāng, Yuhong Wu, Chao Gao, Yong He
Abstract
Exploiting high-performance gas sensors is desirable for the on-site and accurate detection of drug precursor chemical gases. Here, the electron–proton conductivity metal–organic frameworks M 3 (HIB) 2 were designed to discriminate typical drug precursor chemical gases. The strong d-π conjugation and substantial H 2 O ligands in M 3 (HIB) 2 generate conducting pathways for electrons and protons, which contribute to novel gas-sensing properties. Remarkably, Fe 3 (HIB) 2 demonstrates an ultrahigh response of over 379 toward 60 ppm of toluene at room temperature (RT). Furthermore, the adsorption/desorption behaviors of M 3 (HIB) 2 can be tuned by systematically varying the metal center, causing distinctive gas sensing features for pattern recognition of drug precursor chemical gases. The recognition model was constructed using a convolutional neural networks-gated recurrent unit (CNN-GRU) algorithm, exhibiting a high recognition accuracy. The sensing mechanism is revealed by the Lewis and Brønsted acid site adsorption, due to competitive adsorption between H 2 O and analyte gases. This work paves the way for the development of proton–electron dual-conducting MOFs for high-performance gas sensors.