Hierarchical Fe3O4-derived organic/inorganic hybrids constructed by modified bio-inspired functionalization: efficient adsorbents for water-soluble methylene blue and mechanism

Background The development of efficient and sustainable adsorbents is still a challenge for dye removal in practical applications. Here a method to prepare hierarchical Fe 3 O 4 -derived organic/inorganic hybrid adsorbents for methylene blue removal is demonstrated. Typically, two different structured magnetic nanoparticles were synthesized through solvothermal route and chemical co-precipitation (named as S-Fe 3 O 4 and C-Fe 3 O 4 respectively), which were further functionalized by a novel modified mussel-inspired method with dopamine (DA) and (3-aminopropyl)triethoxysilane (KH550), thus obtaining core-shell Fe 3 O 4 /poly(DA + KH550) adsorbents. Results The effects of microstructure, morphology and surface functionalization on the adsorption performance of core-shell Fe 3 O 4 adsorbents were systematically investigated, thus achieving target structurally optimized core-shell Fe 3 O 4 adsorbents. Especially, the maximum adsorption capacity of core-shell S-Fe 3 O 4 /poly(DA + KH550) adsorbent reached 400.00 mg g −1 because of high specific surface area and abundant active adsorption sites. In addition, the adsorption kinetics and adsorption isotherm fitted a pseudo-second-order model and Langmuir model respectively. Conclusion The recycling process of adsorbent is sustainable in economy and energy by applying an external permanent magnet. In summary, the high adsorption capacity, easy separation and excellent reusability of S-Fe 3 O 4 /poly(DA + KH550) core-shell adsorbents make them promising for dye effluent removal. © 2019 Society of Chemical Industry