Urushiol-resourced dopamine analogue as a trigger to construct clay-hexacyanoferrate hydrogel for cesium removal

To guarantee the sustainable development of the nuclear industry, it is vital to have a low-cost, green, and scalable route developed to synthesize efficient adsorbents for rapid and effective remediation of nuclide-contaminated water. In this study, a natural catechol derivative with unsaturated alkyl chain, urushiol, was aminated by mildly thiol-ene click with cysteamine to form a dopamine analogue, which can self-polymerize and trigger the formation of silicate plates into hydrogel framework and in-situ immobilize the potassium copper hexacyanoferrate, an efficient adsorbent, when hexacyanoferrate and excess Cu 2+ were present in the silicate suspension. The chelation between Cu 2+ , poly-urushiol and hexacyanoferrate that assemble the hybrid hydrogel was confirmed by SEM and XPS and the performance of this hydrogel was evaluated in terms of adsorption capacity (214 mg g −1 ), selectivity (K d >10 6 mg L −1 ), kinetics and reversible self-healing behavior with pleasing results obtained. The economic and nature-sourced property of the urushiol offers a green and novel concept to develop a satisfying adsorbing system for Cs + removal.