Simple one-step synthesis of woven amidoximated natural material bamboo strips for uranium extraction from seawater

The uranium(VI) (U(VI)) extraction from seawater was crucial for future energy problems such as increasingly depleted fossil fuels and serious environmental pollution, and it could improve the current situation of limited U(VI) reserves on land. In this study, the natural material bamboo strips (BS) were utilized due to the flexibility and richness of various functional groups, and the amidoximized bamboo strips (AOBS) could be directly prepared by a simple one-step method. The amidoximation of materials not only adjusted the optimal adsorption pH from 4 to 6, but also advanced the hydrophilicity, speeded up the reaction rate (adsorption equilibrium within 1 h, about 0.17 times of BS), and increased the adsorption capacity (q_e = 268.41 mg g⁻¹ at pH = 6, about 1.7 times of BS). Importantly, the AOBS maintained its initial stitchability through flexibility adjustment, and was woven into a macro-shaped adsorbent (AOBS-M). After being placed in the Yellow Sea basin for 30 days, approximately 44.75 g of crude U(VI) (U(VI) content = 40.45 mg) was obtained (q_e = 0.97 mg g⁻¹), and it showed the excellent selectivity for U(VI). The AOBS-M not only overcame the problem that the existing adsorption materials were difficult to achieve macroscopic large-area molding, but also realized the flexibility adjustment during the modification process by controlling the reaction conditions, and promoted the industrial development of U(VI) extraction from seawater.