Research Projects

Abstract: Uranium contamination in aquatic environments poses serious environmental and health risks due to its chemical toxicity and radiological hazards. Covalent organic frameworks (COFs), particularly those with anionic frameworks, show great promise for the effective remediation of uranium. This proposal outlines a dual-functional approach that uses anionic COFs to combine high-capacity adsorption with the visible-light-driven photocatalytic reduction of uranyl ions (UO₂²⁺). The proposal's primary objective is to achieve high selectivity for uranium ions and enhanced degradation kinetics by incorporating redox-active functional groups and photosensitizers into the COF matrix. Our research will focus on synthesizing a series of anionic COFs with high crystallinity, tunable porosity, and photoactive constituents; evaluating their adsorption performance and photocatalytic activity; and elucidating mechanistic pathways for capturing and transforming uranium. This comprehensive strategy could offer a revolutionary solution for the remediation of nuclear effluent by selectively and durably capturing uranium from seawater. We hypothesize that the presence of conjugation and coordination sites for implanting photoactive moieties will facilitate the adsorption of uranyl ions and their photocatalytic reduction under visible light. Our goal is to increase efficiency, minimize resource consumption, and streamline operational procedures for uranium extraction in practical settings by integrating these complementary processes into a single material. Our investigation will emphasize three critical aspects: 1. Systematic synthesis and post-synthetic modification of anionic COFs to optimize uranium adsorption performance. 2. Detailed evaluation of adsorption selectivity, capacity, kinetics, and stability in simulated and real seawater conditions. 3. Integration of photocatalytic functionalities into the COF backbone by embedding visible-light-absorbing photosensitizers (e.g., porphyrin, bipyridine, etc.) to enable light-induced uranium reduction. The proof of concept for an environmentally friendly, regenerable, and renewable uranium harvesting system will be demonstrated through the implementation of a dual-functional approach encompassing photocatalytic transformation and adsorptive capture. Successful implementation of this hybrid approach would not only enhance scientific understanding of multifunctional COFs but also facilitate the deployment of offshore uranium extraction systems, promoting long-term energy security and global sustainability. This initiative is consistent with the United Nations' Sustainable Development Goals (SDGs). For example, SDG 6 (Clean Water and Sanitation) aims to ensure access to clean, secure water for all, SDG 12 (Responsible Consumption and Production) promotes environmentally favorable practices; and SDG 14 (Life Below Water) mitigates the hazards posed by uranium to marine ecosystems.