Sol–Gel Synthesis of CeO ₂ Nanoparticles Using a Gelatine Template for Effective Adsorptive Removal of Arsenate and Fluoride from Water

Abstract In this study, CeO 2 nanoparticles were synthesized by the sol–gel method using gelatine templates. The prepared CeO 2 analyzed by analytical techniques displayed the fluorite structure with uniform sizes of 10–25 nm, a BET‐specific surface area of 65.8 m 2 /g, a pore volume of 0.144 cm 3 /g, and the existence of oxygen vacancies, suggesting their compatibility for adsorption removal of pollutants. The adsorption of arsenate and fluoride on CeO 2 exhibited the maximal adsorption capacity of 224 and 64 mg/g, respectively. The kinetics of the adsorption fitted the pseudo‐second‐order model perfectly. Compared to fluoride, the adsorption of arsenate was found kinetically more but thermodynamically less favored. It can lie on the more stable complexes formed between arsenate and the prepared CeO 2 , the larger size of arsenate ions, and the mesoporosity of the prepared CeO 2 . As a result, the pore of the prepared CeO 2 is filled quickly with arsenate ions, becoming full after a specific time that prevents the filling of further arsenate ions. Moreover, the CeO 2 adsorbent demonstrated its high reusability up to 9 times without losing remarkable adsorption capacity (≤10%). Overall, the prepared CeO 2 can be applied for the treatment of drinking water and wastewater in several regions of Vietnam.