Removal of hexavalent chromium from wastewater by Cu/Fe bimetallic nanoparticles

• Published in: Scientific reports 2021-05, Vol.11 (1), p.1-11, Article 10848
• Main Authors: Ye, Jien, Wang, Yi, Xu, Qiao, Wu, Hanxin, Tong, Jianhao, Shi, Jiyan
• Format: Article
• Language: English
• Subjects: 639/925; 704/172; Chemical reduction; Chromium; Copper; Efficiency; Humanities and Social Sciences; Iron; Load distribution; multidisciplinary; Nanoparticles; Nanotechnology; Photoelectron spectroscopy; Science; Science (multidisciplinary); Transmission electron microscopy; Wastewater; Wastewater treatment; Water treatment; X-ray diffraction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-90414-0

Passivation of nanoscale zerovalent iron hinders its efficiency in water treatment, and loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Synthesized bimetallic nanoparticles were characterized by transmission electron microscopy, Brunauer–Emmet–Teller isotherm, and X-ray diffraction. The results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. The removal of Cr(VI) was better fitted by pseudo-second-order model than pseudo-first-order model. Thermodynamic analysis revealed that the Cr(VI) removal was spontaneous and endothermic, and the increase of reaction temperature facilitated the process. X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(III) and precipitated on the particle surface as hydroxylated Cr(OH) 3 and Cr x Fe 1−x (OH) 3 coprecipitation. Our work could be beneficial for the application of iron-based nanomaterials in remediation of wastewater.