Fabrication of Fe3O4@GO@ZIF-8 nanohybrids via in-situ self-assembly with magnetic collectability for efficient adsorption of As(III) and As(V)

Fe3O4@GO@ZIF-8 nanohybrids were successfully fabricated as a novel magnetic graphene adsorbent via in-situ self-assembly of ZIF-8 and graphene oxide (GO) onto magnetic ferroferric oxide nanoparticles. The adsorbent was thoroughly characterized using various techniques. The results showed that Fe3O4@GO@ZIF-8 exhibits strong magnetic properties, abundant functional groups and a large specific surface area of 779.48 m2 g−1. Additionally, the effects of time, pH, initial concentration and temperature on the adsorption performances of Fe3O4@GO@ZIF-8 for trivalent arsenite (As(III)) and pentavalent arsenate (As(V)) were explored. The results revealed that Fe3O4@GO@ZIF-8 possesses fast reaction kinetics (reaching saturation in approximately 180 min for As(III) and 120 min for As(V)), as well as excellent adsorption capabilities (achieving adsorption capacities of 87.621 mg g−1 for As(III) and 113.37 mg g−1 for As(V)). Furthermore, recycling experiments demonstrated that Fe3O4@GO@ZIF-8 exhibits favorable adsorption ability, enabling easy recovery under an applied magnetic field. These results highlight the magnetic properties, good reusability, and adsorption capacity of Fe3O4@GO@ZIF-8, rendering it highly practical for extracting arsenic wastes in harsh environments.