Preparation and adsorbability of magnetic composites based on cellulose nanofiber/graphene oxide

In this study, a magnetic composite (Fe 3 O 4 @SiO 2 -APTES/GO/CNF) possessed three-dimensional network was prepared by electrostatic self-assembly method based on cellulose nanofiber (CNF)/graphene oxide (GO). The adsorption properties and mechanism of Fe 3 O 4 @SiO 2 -APTES/GO/CNF for methylene blue (MB) were investigated. The experimental results show that the composite material has an obvious three-dimensional network and can be quickly collected under the attraction of external magnets. When the mass ratio of CNF, GO, and Fe 3 O 4 @SiO 2 -APTES is 7: 3.5: 1, the adsorption effect of MB is optimal. Langmuir isothermal adsorption model and pseudo-second-order kinetic model can well describe the adsorption process of MB on the composites, the maximum adsorption capacity is up to 1447 mg g −1 . It is satisfactory that the adsorption capacity for MB remains 83.53% of the original adsorbent after five cycles. The good adsorption and cyclic performance endow it with a broad application prospect in dye wastewater treatment. • A simple electrostatic self-assembly method was used. • The maximum adsorption capacity of the composite for MB is 1447 mg g −1 . • The adsorbent can be easily recycled by external magnets in only 20 s • The adsorption capacity of MB is 83.53% of the initial amount after 5 cycles.