Interpenetrated Cu-Based MOF Features High Iodine Adsorption and I-Doping-Enhanced Conductivity, Adding to Its Waste-to-Utility Approach

Hazardous waste management is a major global issue, with ongoing efforts to reduce it hindered by continuous production from rapid population growth and industrialization. Inadequate technology has hindered the simultaneous collection of hazardous waste from water and vapor phases for sustainable energy applications in the material sector. Here, we present a novel, affordable method for developing a robust MOF (Cu-TPA-BPE IP-MOF) for the sequestration of iodine from the environment. The substantial free void space and 1D-porous channels in its crystal lattice enable the selective absorption of nearly 90% of trace amounts of I₃^- from water. An exceptional distribution coefficient (<i>K</i>_d∼10³ mL/g) indicates a strong affinity for iodine. The accompanying mechanistic insights stem from the ultrahigh iodine selectivity found through extensive experimentally driven computational studies. Iodine absorption as a dopant enhances the conductivity of the hybrid material. Notably, when tested against aluminum metal, the I₂ and I₃^--captured MOF exhibited a moderately high optical-dependent conductivity of 2.89 × 10^-3 S/m with a significant rectification ratio of 20.56, making it a viable candidate for diode fabrication. Additionally, the I₃^--loaded MOF demonstrates high ionic conductivity of 1.14 × 10^-3 S/cm. Conductivity analysis, dependent on concentration, positions the hybrid material to function as a sensor for detecting the iodine concentration in water.