Graphene oxide supported sulfidated nano zero-valent iron (S-nZVI@GO) for antimony removal: The role of active oxygen species and reaction mechanism

Zifang Chi; Shijie Ju; Xinyang Liu; Feiyang Sun; Yuhuan Zhu

doi:10.1016/j.chemosphere.2022.136253

Graphene oxide supported sulfidated nano zero-valent iron (S-nZVI@GO) for antimony removal: The role of active oxygen species and reaction mechanism

Chemosphere. 2022 Dec;308(Pt 1):136253. doi: 10.1016/j.chemosphere.2022.136253. Epub 2022 Aug 31.

Authors

Zifang Chi¹, Shijie Ju², Xinyang Liu², Feiyang Sun², Yuhuan Zhu³

Affiliations

¹ Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, PR China. Electronic address: chizifang@jlu.edu.cn.
² Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, PR China.
³ Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, PR China. Electronic address: 104881010@qq.com.

PMID: 36057347
DOI: 10.1016/j.chemosphere.2022.136253

Abstract

Sulfidated nano zero-valent iron (S-nZVI) was used to remove various pollutants from wastewater. However, the instability, poor dispersibility, and low electron transfer efficiency of S-nZVI limit its application. Herein, graphene oxide supported sulfidated nano zero-valent iron (S-nZVI@GO) was successfully synthesized using graphene oxide (GO) as a carrier. The properties of S-nZVI@GO were characterized by scanning electron microscopy coupled to X-ray photoelectron spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) concerning the surface morphology, crystalline structure, and elemental components. S-nZVI@GO displayed an excellent capacity for antimony (Sb) removal under aerobic conditions (96.7%), with a high adsorption capacity (Q_max = 311.75 mg/g). It maintained a high removal rate (over 90%) during a wide pH range (3-9). More importantly, S-nZVI@GO activated the molecular oxygen in water via a single-electron pathway to produce •O₂－ and H₂O₂, and then oxidized trivalent antimony (Sb(III)) to pentavalent antimony (Sb(V)) and further separated it by synergistic adsorption and co-precipitation. Therefore, S-nZVI@GO shows excellent potential for Sb contamination remediation.

Keywords: Antimony removal; Molecular oxygen activation; Oxidation–adsorption; S-nZVI@GO.