Facile synthesis of recycling Fe3O4/graphene adsorbents with potassium humate for Cr(VI) removal

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2019-01, Vol.560, p.384-392
• Main Authors: Wang, Xiaopeng, Lu, Jing, Cao, Baoyong, Liu, Xueming, Lin, Zhang, Yang, Chao, Wu, Ronglan, Su, Xintai, Wang, Xuefeng
• Format: Article
• Language: English
• Subjects: Adsorption; Hexavalent chromium; Magnetic nanoparticles (NPs); Potassium humate; Recycle
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2018.10.036

[Display omitted] Potassium humate possesses a wide variety of oxygen-containing functional groups and has good adsorption and complexation properties for many kinds of transition metal ions. In this work, a simple and separable route had been developed to synthesize Fe3O4/graphene nanocomposite, derived from potassium humate, were employed for the effective adsorption of Cr(VI) in aqueous phase. In addition, the Fe3O4/graphene nanocomposite prepared at 600 °C (S-600) showed a maximum adsorption capacity of 280.6 mg/g for Cr(VI) and good cycling performance, which was much higher than those reported graphene-based adsorbents and other conventional adsorbents. The adsorptive behavior was well fitted to the Langmuir isotherm model. The adsorption kinetics for removal of Cr(VI) agreed with pseudo-second-order equation, which indicates a kind of chemical adsorption. Its superior adsorption performance might be due to the effective adsorption sites at the surface and formation of FeOH2+ on the surface of Fe3O4/graphene. This work provided a promising approach for the removal of Cr(VI) from wastewater using a Fe3O4/graphene nanocomposite, which shows a huge number of application prospects.