Fe3O4@C@polyaniline trilaminar core–shell composite microspheres as separable adsorbent for organic dye

Uniform core–shell Fe3O4@C@polyaniline (PANi) composite microspheres have been prepared via simple in situ polymerization in the absence of surfactants. In this case, the carbon intermediate layer plays an important role in the formation of trilaminar core–shell structure. By simply adjusting the molar ratio of aniline to Fe3O4, the thickness of the polymer shell can be tuned from about 27 to 62 nm. The obtained Fe3O4@C@PANi trilaminar core–shell composite microspheres are used as magnetic adsorbent for the removal of methyl orange (MO) dye from aqueous solution, exhibiting an excellent adsorption capability of 120.2 mg g−1 for MO and retaining about 81% of the removal efficiency after five adsorption–desorption cycles. The adsorption isotherms and kinetics are well described by the Langmuir and pseudo-second-order models respectively. The Fe3O4@C@PANi composite microspheres could be a good candidate in the waste water treatment for the removal of organic dyes.