Ternary cross-coupled nanohybrid for high-efficiency 1H-benzo[ d ]imidazole chemisorption

Abstract

1H-Benzo[d]imidazole (BMA) has been considered as an emerging pharmaceutical organic contaminant, leading to the increasing BMA detection in wastewaters and need to be removed from ecosystem. This study investigated a highly synergistic BMA chemisorption using a novel ternary cross-coupled nanohybrid [γ-APTES]-Fe₃O₄@PAN@rGO. Magnetic nanoparticles (Fe₃O₄) were in situ core-shell co-precipitated with polyacrylonitrile polymer (PAN). Then, the prepared Fe₃O₄@PAN was decorated on hexagonal arrays of reduced graphene oxide (rGO) inside the framework of γ-aminopropyltriethoxysilane ([γ-APTES]). The final nanohybrid [γ-APTES]-Fe₃O₄@PAN@rGO produced adjacent inter-fringe distances of 0.2–0.4 nm corresponded well to (111), (220), and (311) parallel sub-lattices with two oblique intersections at 90° right angle and 60° triangle. The BMA adsorption was favorable in neutral pH 7, aroused temperature (50 °C), and controlled by endothermic process. The identified maximum adsorption capacity of 221.73 mg g⁻¹ was 30% higher than the reported adsorbents. The adsorption mechanisms include ion exchange, hydrogen bond, dipole-dipole force, π-conjugation, electrostatic, and hydrophobic interaction.

Graphical abstract

The synthetic route of novel nanohybrid [γ-APTES]-Fe₃O₄@PAN@rGO was investigated. After BMA adsorption, the adsorbent surface was entirely changed, thus an efficiently facile magnetic separation within 8s. [γ-APTES]-Fe₃O₄@PAN@rGO formed different oblique intersections of 60° and 90° sub-lattices