Vx-Na2TiOSiO4 MWNTs for uranium extraction from seawater and recovery from nuclear waste

Uranyl ion pollution is a serious environmental problem, and developing novel adsorption materials is essential for uranyl ion removal. V-doped Na2TiOSiO4 multiwalled nanotubes (Vx-Na2TiOSiO4 MWNTs) were prepared by an effective hydrothermal process and their uranyl ion adsorption properties were investigated. The special morphology, high specific surface area, and surface potential made MWNTs an excellent adsorbent. Appropriate doping can further improve the adsorption performance of nanotubes. The saturated adsorption capacities of nanotubes in aqueous solution and simulated seawater were 593.2 and 236.9 mg/g, respectively, and can reach 684.6 and 287.0 mg/g after appropriate doping. Proposed and proved the adsorption mechanism of nanotubes was the surface electrostatic adsorption mechanism, the Na+ replacement, and uranyl ion crystallization. In addition, nanotubes have excellent selectivity and recyclability. The finding in this work provides a fundamental understanding of the efficient usage of Vx-Na2TiOSiO4 MWNTs in practical applications.