Easy separated 3D hierarchical coral-like magnetic polyaniline adsorbent with enhanced performance in adsorption and reduction of Cr(VI) and immobilization of Cr(III)

Effective Adsorption of Hexavalent Chromium and Divalent Nickel Ions from Water through Polyaniline, Iron Oxide, and Their Composites

“…Similarly a peak appeared at 1044.2 cm −1 which indicated intrinsic vibrations of the Cr−O bond, thus confirming the adherence of Cr(VI) on to Fe 3 O 4 . Adsorption of Cr(VI) onto PANI was determined by the increase in intensity of the peak at 1005.2 cm −1 while in composites the same was observed at 1039.6 cm −1 as reported elsewhere [57,58]. Similar results were obtained after adsorption of Ni(II) on all adsorbent materials, however; shifting of % transmittance was less as compared to Cr(VI), indicating stronger interactions between Cr(VI) and adsorbent materials as compared to Ni(II) [59].…”

Polyaniline/Nanomaterial Composites for the Removal of Heavy Metals by Adsorption: A Review

“…The adsorption results showed that the maximum adsorption capacity was 111.11 mg/g at pH 9, achieved in 60 min; however, an increase in the absorbent dosage was found to have a negative effect on the adsorption of Pb(II). Lyu et al [61] investigated the synthesis of a 3D hierarchical coral-like micro/nanostructural polyaniline labeled CL-PANI and two magnetic nanocomposites that exhibited excellent adsorption and easy separation performance with two different modes: a CL-PANI core coated a shell of Fe 3 O 4 NPs, and a core of Fe 3 O 4 NPs protected by a CL-PANI shell. Surface analysis of the prepared CL-PANI@Fe 3 O 4 illustrated that CL-PANI was well coated by Fe 3 O 4 NPs with a diameter of 10 nm and a uniform distribution, confirmed by the presence of lattice fingers with an interplanar distance of 0.3 nm, correlated to the magnetite phase.…”

“…Most of the authors used NaOH, HCl, or HNO 3 solutions for the desorption of absorbed metals from the considered nanocomposite. For example, Lyu et al [61] evaluated the desorption of Cr(VI) from polyaniline-coated magnetic nanoparticles using 0.1 M NaOH solution for 30 min; the authors reported that 80% of the adsorption capacity was maintained after 10 consecutive cycles. Fan et al [75] reported the regeneration of a polyaniline/graphene oxide nanocomposite using 0.1 M HNO 3 eluent for 24 h; no obvious change in adsorption capacity was observed within seven cycles.…”

Recent advances in hexavalent chromium removal from aqueous solutions by adsorptive methods

“…45,55,[151][152][153] RGO-Fe 3 O 4 nanocomposites prepared by a solvothermal method were evaluated for the removal of hexavalent chromium. 153 Ma et al 151 155,156 Hierarchical porous carbon adsorbent with 3D interconnected structure was prepared from a three-system precursor of resorcinol-melamine-formaldehyde anchored on nanocrystalline cellulose through a sol-gel process. 157 The material exhibited a higher adsorption capacity of 463 mg g À1 at pH 1 when evaluated for Cr(VI) removal with a batch method.…”