Ion-exchange induced multiple effects to promote uranium uptake from nonmarine water by micromotors

As the fundamental resource in nuclear energy, uranium is a sword of two sides, due to its radioactive character that could cause severe impact to the environment and living creatures once released by accident. However, limited by the passive ion transport, the currently available uranium adsorbents still suffer from low adsorption kinetics and capacity. Here, we report a self-driven modular micro-reactor composed of magnetizable ion-exchange resin and adsorbents that can be used to dynamically remove uranium from nonmarine waters. Because of the long-range pH gradient and phoretic flow established by the recyclable ion-exchange resin, the micro-reactor shows a fast uranium adsorption rate and reaches a uranium extraction capacity of 629.3 mg g^-1 within 10 min in 30 ppm uranium solution, as well as good recyclability in repeated use. Numerical simulation result confirms that the phoretic flow and electric field accelerate uranium transport to the adsorbent. Our work provides a new solution for the removal of radioactive uranium with high efficiency.