Synthesis of La₂(C₂O₄)₃ nanoprisms decorated with Fe₃O₄@m(ZrO₂‐CeO₂) nanospheres and their application for effective fluoride removal

Abstract

BACKGROUND: Composites of defluoridation adsorbents based on rare earths have attracted increasing interest recently, but most of them were amorphous. The main reason for this situation is that morphology control has not been paid enough attention, because the related preparation methods are relatively sparse. Consequently, novel preparation methods are urgently needed. RESULTS:In this study, a novel La-Zr-Ce tri-metal adsorbent with regular morphology was facilely synthesized. There were two morphological shapes in the composite. Nanoprisms of La 2 (C 2 O 4 ) 3 were decorated with mesoporous nanospheres of Fe 3 O 4 @m(ZrO 2 -CeO 2 ). The samples were investigated by energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). Several affecting factors such as initial fluoride concentration, contact time, coexisting anions and pH were studied in detail. The balance data were analyzed by Langmuir, Freundlich and Langmuir-Freundlich isotherm models. The nanocomposite had a maximum sorption capacity of 117.3 mg g −1 toward fluoride, which is among the highest ever reported for fluoride adsorbents. Furthermore, it had a wide applicable pH range of 2-10 and high anti-interference ability. The different functions of La 2 (C 2 O 4 ) 3 nanoprisms and Fe 3 O 4 @m(ZrO 2 -CeO 2 ) nanospheres in the composite have been elucidated. These two components were found to synergistically improve F − adsorption performance via their individual merits. CONCLUSION: The adsorbent had high potential to treat F − contaminants in real application, and the method reported here is considered to be helpful for developing more highly effective adsorbents. Adsorption isothermsAdsorption isotherms of the adsorbents were investigated by Langmuir (Equ. S2 in File S1), Freundlich (Equ. S3 in File S1) and J Chem Technol Biotechnol 2019; 94: 3650-3660 /jctb CONCLUSIONS A novel La-Zr-Ce tri-metal adsorbent with regular morphology was successfully synthesized by step-by-step precipitation methods and showed excellent fluoride removal performance. There J Chem Technol Biotechnol 2019; 94: 3650-3660

Magnetic Composite for Efficient Adsorption of Iron and Magnesium Ions from Aqueous Solution

“…K L (L/mg) is a constant on the Langmuir isotherm, while K F is the Freundlich constant (mg/g)(mg/L). The intensity and surface heterogeneity at different concentrations is denoted by 1⁄n (Wang et al, 2019).…”