Engineering 3D graphene-like carbon-assembled layered double oxide for efficient microplastic removal in a wide pH range

Gang Peng; Mingxue Xiang; Wenzhe Wang; Zilin Su; Huilin Liu; Yuting Mao; Yu Chen; Ping Zhang

doi:10.1016/j.jhazmat.2022.128672

Engineering 3D graphene-like carbon-assembled layered double oxide for efficient microplastic removal in a wide pH range

J Hazard Mater. 2022 Jul 5:433:128672. doi: 10.1016/j.jhazmat.2022.128672. Epub 2022 Mar 11.

Authors

Gang Peng¹, Mingxue Xiang¹, Wenzhe Wang¹, Zilin Su¹, Huilin Liu², Yuting Mao³, Yu Chen⁴, Ping Zhang⁵

Affiliations

¹ Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China.
² Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
³ Office of MRL Development Committee of Jiangxi Province, Nanchang, 330046, China.
⁴ School of Environmental and Chemical Engineering, Shanghai University, Shanghai, PR China.
⁵ Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China. Electronic address: zhangping@ncu.edu.cn.

PMID: 35393125
DOI: 10.1016/j.jhazmat.2022.128672

Abstract

Microplastics (MPs) elimination is becoming an intractable environmental issue due to their nonbiodegradable nature and wide spreading，especially in the case of wastewater containing acid or alkaline effluent. To target the dilemma, this work rationally engineered a robust three-dimensional graphene-like carbon assembled layered double oxide material (defined as G@LDO) from hierarchical organic LDH (i.e., 3D OLDH) via a "precursor-calcination" strategy. In virtue of the mutually protection effect of graphene-like carbon (G) and LDO, the engineered G@LDO featured the preeminent acid and base resistance for polystyrene (PS, as representative of MPs) removal. Especially and importantly, the removal efficiency of PS was ≥ 80% at pH= 3-11, even nearly 60% PS was removed at pH= 1 and 13. The maximum adsorption ability of G@LDO for PS was estimated to be 209.39 mg/g by a Langmuir isotherm model, much superior to that of pure G, LDO, and 2D G@LDO. Furthermore, the removal pathway was analyzed by kinetic together with thermodynamic study, revealing that the PS removal on G@LDO was an exothermic reaction controlled by chemisorption. By systematical characterization and DFT calculation, the removal mechanism of PS was revealed to be hydrogen bond and complexation associated with LDH recovered from LDO and π-π conjunction from G. Notably, the existence of sulfure (S) in the carbon network was also identified as significant component in PS removal via p-π interaction. Overall, this work not only provides a effective candidate for microplastics removal in a wide applicable scope (especially acid/alkaline effluent), shedding light on environmental remediation, but also opens a new anvenue for the disposal of LDHs adsorbed organic in a high value-added manner.

Keywords: Graphene-like carbon composites; Layered double oxide; Microplastic; Removal; Resource-reutilization.