▎ 摘　　要

NOVELTY - Preparing chelate/oxidized graphene composite film comprises (a) uniformly placing graphene oxide graphene in a solvent to obtain graphene dispersion, (b) dissolving polydentate ligands in the solvent to obtain chelating agent, (c) dissolving metal ion salt in water to obtain metal ion salts solution, and (d) carrying out drying treatment, and circularly spin-coating the oxide graphene, chelating agent and metal salt solution on support body layer by layer from bottom to top to form film layer to obtain product. Where the solvent comprises water. USE - The metal chelate/graphene oxide composite membrane material is useful for selective separation of ion (claimed), and also useful for monovalent/divalent ion screening and other related fields e.g. refining brine, and extracting lithium from salt lake and hard water soften. ADVANTAGE - The metal chelate/oxidized graphene composite film has high permeability and selectivity in monovalent and divalent salt solution system. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for metal chelate/graphene oxide composite membrane material.