Magnetic graphene oxide-chitosan nanohybrid for efficient removal of aqueous Hg(Π) and the interaction mechanism

• Published in: Journal of molecular liquids 2023-01, Vol.370, p.121050, Article 121050
• Main Authors: Bulin, Chaoke, Zheng, Rongxiang, Song, Jinling, Bao, Jinxiao, Xin, Guoxiang, Zhang, Bangwen
• Format: Article
• Language: English
• Subjects: Adsorption; Interaction mechanism; Magnetic graphene oxide-chitosan; Removal performance
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2022.121050

[Display omitted] •Fe3O4-graphene oxide-chitosan (MGC) was facilely fabricated.•MGC removes 84.96 % of Hg(Π) in 8 min, with an adsorption quantity 339.82 mg·g−1.•HSAB theory illuminates the plausible adsorption sites in MGC.•–C(=O)NH– was formed via amidation reaction between graphene oxide and chitosan.•–C(=O)NH– and C–O, as well as O2– in Fe3O4 contributes to Hg(Π) uptake. Magnetic adsorbent combining graphene and chitosan have exhibited encouraging application in wastewater remediation. Herein, magnetic graphene oxide-chitosan nanohybrid (MGC) was readily obtained via synchronous reduction-precipitation under a mild experimental condition and utilized as adsorbent to remove aqueous Hg(Π). The interaction mechanism between MGC and Hg(Π) was unveiled via spectroscopic analyses, adsorption fittings and the hard-soft acid-base theory. Results present, 95 % of –NH2 in chitosan was transformed into –C(=O)NH– via amidation with –OH, enabling the outperformance of MGC over any single phase. MGC efficiently adsorbs 339.82 mg·g−1 of Hg(Π) in 8 min, during which the counterions in Hg(NO3)2·H2O were simultaneously adsorbed via chemical interaction featured by electron donation. Specifically, –C(=O)NH–, C–O and O2– contribute to Hg(Π) uptake, while Fe(III), Fe(Π) contribute to NO3– uptake. This work may provide inspiration for developing efficient adsorbent based on magnetic graphene oxide-chitosan.