Electronic Textiles Based on Conductive Metal–Organic Frameworks as Scavengers and Sensors of Toxic Oxyanions from Water

Water contamination by toxic oxyanions poses a severe threat to ecosystems and human health. While various adsorbents have been developed for oxyanion sequestration, designing a single material that simultaneously achieves high selectivity, rapid adsorption kinetics, and real-time sensing capabilities remains a challenge. This study explores the first use of layered, conductive metal-organic frameworks (cMOFs) based on hexahydroxy- and hexaimino-triphenylene (HHTP and HITP) cores coordinated with nickel and copper for the dual sensing and filtration of oxyanions from water. Systematic investigations of Ni3(HHTP)2, Cu3(HHTP)2, Ni3(HITP)2, and Cu3(HITP)2 reveal that Ni3(HITP)2 exhibits unprecedented adsorption capacities, capturing up to 827 mg of MnO4 - and 497 mg of Cr2O7 2- per gram of MOF, while filtering up to 99% of these oxyanions within 10 min of exposure. Ni3(HITP)2 also demonstrates high applicability in real-world scenarios, maintaining a remarkable adsorption performance across various water matrices, pH conditions, and competing anion interferences. Spectroscopic and computational investigations reveal a multimechanistic scavenging process involving chemisorption, physisorption, and redox reactions. Grafting Ni3(HITP)2 onto cotton textiles via a layer-by-layer approach yields mechanically robust, easy to handle, and flexible electronic textile capable of filtering oxyanions for up to 32 cycles without performance loss, while allowing their detection with high sensitivity and low detection limits reaching 2.2 ppm for MnO4 - and 6 ppm for Cr2O7 2-. Taken together, these findings pave the way for MOF-based next-generation water treatment technologies that integrate efficient filtration and real-time sensing capabilities.