Triphenylene-Based 2D cMOFs: Unraveling the H<sub>2</sub>S Sensing Mechanism and Applications for a Real-Time Wireless Chemiresistive Sensor
Mingyu Jeon, Joon-Seok Lee, Minhyuk Kim, Jaewoo Seo, Honghui Kim, Hoi Ri Moon, Seon‐Jin Choi, Jihan Kim
Abstract
Two-dimensional conductive metal–organic frameworks (2D cMOFs) stand at the forefront of chemiresistive sensing innovations due to their high surface areas, distinctive morphologies, and substantial electronic conductivity. Particularly, 2D cMOFs crafted using 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and 2,3,6,7,10,11-hexaiminotriphenylene (HITP) organic ligands have garnered a large amount of attention due to their designable active sites and proper conductive characteristics. Nevertheless, a deeper exploration into their sensing mechanisms is imperative for a comprehensive understanding of the intrinsic chemistry, which is crucial for the intricate design of specialized 2D cMOF chemiresistive sensors. In this study, we fabricate six M-HXTP (M = Co, Ni, and Cu; X = H and I) chemiresistive sensors, focusing on the application of hydrogen sulfide (H 2 S) detection. Among these, the 2D cMOFs incorporating Cu metal manifested a remarkably enhanced response to H 2 S. A combination of experimental and computational studies unveils the mechanisms of sulfur oxidation and Cu reduction, wherein distortion of the reduced MX 4 cluster markedly amplifies the sensing response. Lastly, a real-time and portable wireless H 2 S sensing module has been demonstrated by using the Cu-HHTP composite material, highlighting the substantial practical significance and potential applicability.