Adsorption and trace detection of copper ion by three-dimensional porous graphene composite gel

In this paper, a polydopamine-graphene composite gel (PDA-GA) was prepared from graphene oxide by a facile in-situ reduction assembly method using ascorbic acid combined with dopamine (DA). The morphology and microstructure of PDA-GA were characterized by SEM, XRD, FTIR, BET-BJH, and MIP, and the adsorption behavior of PDA-GA for Cu2+ was studied. Furthermore, the response ability of graphene composite gel-modified glassy carbon electrode (PDA-GH-GCE) to trace Cu2+ was investigated by linear sweep anodic stripping voltammetry. Results showed that when the mass ratio of graphene oxide to DA was 1:3, the adsorption effect of PDA-GA for Cu2+ was the best, and the adsorption capacity reached 316 mg/g. PDA-GA-GCE was sensitive to trace Cu2+, and the detection limit could reach 1.6 × 10−7 mol/L.