Enhanced iodine capture via covalently integrated NH₂-UiO-66@ZA-COF hybrid structures
Shaikha S. AlNeyadi
Abstract
• High iodine capture NH₂-UiO-66@ZA-COF achieves an iodine uptake of 5.63 g ⋅ g⁻¹ , surpassing previous MOF-COF hybrids. • Robust core-shell hybrid Covalent bonding ensures structural stability and enhanced adsorption properties. • Superior reusability Retains 94% adsorption capacity after five cycles, demonstrating long-term durability. • Scalable & cost-effective Designed for practical industrial applications with economic feasibility. • Sustainable nuclear waste management Offers an efficient, reusable material for iodine sequestration, improving environmental safety. Nuclear power remains a crucial energy source, yet the management of radioactive waste, particularly iodine isotopes, presents significant environmental and health concerns due to their volatility and long half-life. Developing advanced materials for effective iodine sequestration is vital for ensuring the safe disposal of nuclear waste. Metal-Organic Framework (MOF)@Covalent Organic Framework (COF) hybrid materials offer a promising strategy, combining the high porosity and stability of MOFs with the tunable functionality of COFs. In this study, we introduce NH₂-UiO-66@ZA-COF, a novel MOF@COF hybrid synthesized via the in-situ growth of a ZA-COF shell on an NH₂-UiO-66 core using a Schiff-based reaction. This covalently bonded core-shell structure enables fine-tuned interface properties that significantly enhance iodine adsorption capacity. Our results demonstrate that NH₂-UiO-66@ZA-COF exhibits an exceptional iodine vapor uptake of 5.63 g⋅g⁻¹, surpassing previously reported MOF-COF hybrids such as NH₂-UiO-66@Br-COFs (3.73 g⋅g⁻¹) and UiO-66-NH₂@TAPT-COF (0.24 g⋅g⁻¹). Moreover, NH₂-UiO-66@ZA-COF hybrids display outstanding reusability, retaining over 94% of their iodine adsorption capacity after five cycles. The material maintains its structural integrity under harsh environmental conditions, demonstrating long-term stability, scalability, and cost-effectiveness. This study contributes to the advancement of sustainable radioactive waste management technologies by offering an efficient and reusable material for iodine capture, reducing the environmental impact of nuclear waste storage while providing a scalable and cost-effective solution for industrial applications. These findings highlight the potential of NH₂-UiO-66@ZA-COF as a high-performance material for radioactive iodine sequestration, paving the way for more sustainable nuclear waste management solutions. A) Schematic representation of NH₂-UiO-66@ZA-COF material demonstrating its high iodine uptake capacity (5.83 g⁻¹) for iodine capture from industrial emissions. B) Experimental data showcasing the time-dependent iodine uptake capacity at 80 °C, indicating rapid adsorption and saturation over 25 h, with visual transformation of material color as evidence of iodine absorption