Enhanced Stretchable 2D Metal-Graphene Membranes with Superior Mechanical Properties for Sieving Lithium from Brine

Designing mechanically robust, 2D membranes with elastic properties is crucial for advancing separation technologies, particularly in demanding environments such as saline lakes. Here, an innovative approach, the synthesis of silver nanosheets within graphene oxide (GO) membranes to form a 2D silver-graphene heterojunction, is introduced. This membrane exhibits exceptional mechanical strength (stress tolerance of 4.26 MPa and strain capacity of 123.03%), attributed to the reinforcing effect and ductility of silver nanosheets interacting synergistically with GO layers. Notably, the membrane demonstrates high selectivity for lithium ions in Salt Lake brine (Li⁺/Mg²⁺ ≈ 29.0, Na⁺/Mg²⁺ ≈ 183.3). Through dynamic stretching, the membrane enables precise modulation of ion permeability and selectivity, highlighting its versatility and practicality in complex separation processes. This study marks a significant advancement in membrane design, underscoring its potential in addressing challenges posed by diverse industrial applications, particularly in saline environments.