In-situ growth of polyoxometalate-based metal-organic frameworks on wood as a promising dual-function filter for effective hazardous dye and iodine capture

Environmental contaminants have become a major global issue in recent years. Adsorption has been considered as one of the most effective methods of removing contaminants from the environment. However, there are still some challenges to their practical applications, such as complex preparation, expensive cost, and low efficiency. In this study, we used solvothermal conditions to introduce polyoxometalate-based metal-organic frameworks (POMOFs) into a natural wood (POMOF/wood) for the effective removal of organic dye and iodine capture. The Keggin-type POM anions (PMo12) with a highly negative charge were encapsulated to adjust the charge of the UiO-66 MOF, where the charge overcompensation in the POMOFs allows them to efficiently adsorb cationic dyes. Benefiting from the unique microstructure of wood, the POMOF/wood exhibits up to 94.07% and 95.23% removal efficiency for cationic dyes methylene blue (MB) and gentian violet (GV) with a permeance of 1.0×104 L·m−2·h−1·bar−1. Furthermore, the POMOF/wood has high adsorption capacity for capturing iodine, with a maximum adsorption capacity of 1232.8 mg·g−1 in vapor. We believe that a low-cost and scalable filter is advantageous for environmental remediation and this work provides a promising strategy for developing more multifunctional POMOF/wood materials.