Facile fabrication of self-assembled lamellar PANI-GO-Fe3O4 hybrid nanocomposites with enhanced adsorption capacities and easy recyclicity towards ionic dyes

Although adsorption by nanomaterial adsorbents represents a promising approach to remove the dye pollutants in water, the easy agglomeration and low recycling has limited such a prospective application. Herein, we developed a lamellar PANI-GO-Fe3O4 hybrid nanosheet adsorbent by an in-situ polymerization strategy in a hydrothermal reactor with Fe3O4 as an intercalant and GO (graphene oxide) as a template for PANI. Besides the merits of easy magnetic separation ability, the PANI-GO-Fe3O4 hybrid adsorbent also shows a high adsorption capacity of 252.7 and 181.0 mg/g for congo red (CR) and methyl orange (MO) dyes, respectively, quite higher than that of PANI-Fe3O4 and many similar adsorbents in literature. The adsorption behavior followed the quasi-secondary kinetic model and the adsorption isotherms were well fitted with the Langmuir model at 298 K, 313 K and 333 K. After 5 cycles of adsorption and desorption, the removal rates of CR and MO dyes by PANI-GO-Fe3O4 can still reach 88.5% and 76.3%. The superiority of PANI-graphene-Fe3O4 hybrid adsorbent was mainly ascribed to its high dispersibility, thin nanosheets morphology, and Tr-TC stacking/electrostatic interactions with the dyes. This work provides a new direction to promote the separable high-performance adsorbents for removing the ionic dyes contamination from waste water.