One-step uranium extraction and brine desalination via adsorptive pervaporation by graphene-oxide scaffold membranes

The ocean reserves nearly four billion tons of uranium, providing an inexhaustible supply of nuclear energy if the limits of ultralow U(VI) concentration (3.3 µg·L^-1) are addressed. Membrane technology is promising to make this happen by simultaneous U(VI) concentration and extraction. Herein, we report a pioneering adsorption-pervaporation membrane for efficient enrichment and capture of U(VI) along with clean water production. A bifunctional poly(dopamine-ethylenediamine) and graphene oxide 2D scaffold membrane was developed and further crosslinked by glutaraldehyde, capable of recovering over 70% U(VI) and water from simulated seawater brine, which validates the feasibility of one-step water recovery, brine concentration, and uranium extraction from seawater brine. Moreover, compared with other membranes and adsorbents, this membrane exhibits fast pervaporation desalination (flux: 153.3 kg·m^-2·h^-1, rejection: >99.99%) and excellent uranium capture properties of 228.6 mg·m^-2 benefiting from plentiful functional groups provided by embedded poly(dopamine-ethylenediamine). This study aims to provide a strategy for recovering critical elements from the ocean.