Strong Adsorption of Arsenite and Phosphate from Aqueous Solution Using La2O3–CeO2 Composite

Abstract

In the present paper, the synthesis of La2O3–CeO2 composite using the sol–gel combustion method with gelatin as a template and its application for arsenite and phosphate removal are demonstrated. The obtained composite was characterized using thermal analysis (TG–DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy elemental mapping (EDX-elemental mapping). It is found that the La–Ce bimetallic oxide consists of nanoparticles of La2O3 and CeO2 with a size of around 10–20 nm. The La2O3 and CeO2 particles in the composite are highly dispersed. The adsorption of arsenite and phosphate from aqueous solutions on the La2O3–CeO2 composite was investigated at ambient temperature utilizing a batch technique. The arsenite and phosphate adsorption capacity derived from the Langmuir isotherm is 102.5 and 193.3 mg g−1, respectively, which is higher than those reported in the previous papers. The material does not lose much capacity even after eight cycles. The high capacity for phosphate adsorption at low and high concentrations enables the La2O3–CeO2 composite to become a potential material for water and wastewater treatment.