Triphenylene-Based\n2D cMOFs: Unraveling the H<sub>2</sub>S Sensing Mechanism and Applications\nfor a Real-Time Wireless\nChemiresistive Sensor

Two-dimensional conductive metal–organic frameworks\n(2D\ncMOFs) stand at the forefront of chemiresistive sensing innovations\ndue to their high surface areas, distinctive morphologies, and substantial\nelectronic conductivity. Particularly, 2D cMOFs crafted using 2,3,6,7,10,11-hexahydroxytriphenylene\n(HHTP) and 2,3,6,7,10,11-hexaiminotriphenylene (HITP) organic ligands\nhave garnered a large amount of attention due to their designable\nactive sites and proper conductive characteristics. Nevertheless,\na deeper exploration into their sensing mechanisms is imperative for\na comprehensive understanding of the intrinsic chemistry, which is\ncrucial for the intricate design of specialized 2D cMOF chemiresistive\nsensors. In this study, we fabricate six M-HXTP (M = Co, Ni, and Cu;\nX = H and I) chemiresistive sensors, focusing on the application of\nhydrogen sulfide (H<sub>2</sub>S) detection. Among these, the 2D cMOFs\nincorporating Cu metal manifested a remarkably enhanced response to\nH<sub>2</sub>S. A combination of experimental and computational studies\nunveils the mechanisms of sulfur oxidation and Cu reduction, wherein\ndistortion of the reduced MX<sub>4</sub> cluster markedly amplifies\nthe sensing response. Lastly, a real-time and portable wireless H<sub>2</sub>S sensing module has been demonstrated by using the Cu-HHTP\ncomposite material, highlighting the substantial practical significance\nand potential applicability.