The preparation of a novel iron/manganese binary oxide for the efficient removal of hexavalent chromium [Cr(vi)] from aqueous solutions. Issue 18 (12th March 2020)

• Record Type: Journal Article
• Authors: Yang, Chuanxi; Ju, Tiantian; Wang, Xiaoning; Ji, Yujia; Yang, Cheng; Lv, Haojie; Wang, Ying; Dong, Wenping; Dang, Feng; Shi, Xifeng; Wang, Weiliang; Fan, Yuqi
• Is Part Of: RSC advances. Volume 10:Issue 18(2020)
• Page Start: 10612
• Page End: 10623
• Publication Date: 2020-03-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra10558a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A novel Fe–Mn binary oxide adsorbent prepared via "co-precipitation and hydrothermal" method, for the efficient and fast removal of Cr(vi ). Abstract : To remove hexavalent chromium Cr(vi ) efficiently, a novel Fe–Mn binary oxide adsorbent was prepared via a "two-step method" combined with a co-precipitation method and hydrothermal method. The as-prepared Fe–Mn binary oxide absorbent was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectra (FTIR), thermogravimetric analysis (TGA), zeta potential, BET and X-ray photoelectron spectroscopy (XPS). The results indicated that the morphology of the adsorbent was rod-like with length of about 100 nm and width of about 50–60 nm, specific surface area was 63.297 m 2 g −1, has the composition of α-Fe2 O3, β-MnO2 and MnFe2 O4 and isoelectric point was observed at pH value of 4.81. The removal of Cr(vi ) was chosen as a model reaction to evaluate the adsorption capacity of the Fe–Mn binary oxide adsorbent, indicating that the Fe–Mn binary oxide adsorbent showed high adsorption performance (removal rate = 99%) and excellent adsorption stability (removal rate > 90% after six rounds of adsorption). The adsorption behavior of the Fe–Mn binary oxide was better represented by the Freundlich model (adsorption isotherm) and the pseudo-second-order model (adsorption kinetic), suggesting that the adsorption process was multi-molecular layer chemical adsorption. The possible adsorption mechanism of the Fe–Mn binary oxide for the removal of Cr(vi ) included the protonation process and the electrostatic attraction interactions.