▎ 摘　　要

NOVELTY - Preparing metal ion cross-linked graphene film comprises (i) adding graphene oxide (GO) powder into deionized water and ultrasonically disperse to obtain GO dispersion liquid; (ii) obtaining metal salt solution, where the metal salt is a divalent metal salt or a trivalent metal salt; (iii) adding the metal salt solution into the GO dispersion liquid and stirring until uniformly dispersed, and obtaining the GO dispersion liquid of metal ion pre-crosslinking; (iv) obtaining the GO (GOMn+) film of metal ion crosslinking by the GO dispersion liquid of metal ion precrosslinking by vacuum filtration; and (v) placing the GO-manganese film in a petri dish, and placing the petri dish as a whole into a weighing bottle, adding hydroiodic acid (HI) into the weighing bottle while avoiding direct contact with the film, using parafilm to seal the weighing bottle, and put it into an oven for steam reduction to obtain a metal-crosslinked reduced graphene oxide (rGO) (rGO-Mn+) film. USE - The method is useful for preparing metal ion cross-linked graphene film. ADVANTAGE - The graphene film is conducive to the improvement of the toughness of graphene films, and has higher bond energy, which is more conducive to the improvement of the strength of the graphene film and increases strength of graphene films cross-linked by trivalent metal ions by 1.64 times.