Highly Selective and Effective Adsorption of Ionic Dyes Using Reusable CeO 2 –SiO 2 Nanoadsorbents

ABSTRACT CeO 2 –SiO 2 nanoadsorbents synthesized via a simple and energy‐efficient approach were used for the removal of ionic dyes from single and binary aqueous solutions. The effects of pH, temperature, contact time, and adsorbate/adsorbent dosage on adsorption performance were examined as a function of the CeO 2 –SiO 2 ratio. Adsorption isotherms, kinetics, and thermodynamic parameters were interpreted using characterization data and theoretical models. The adsorbent with the highest CeO 2 content exhibited the best adsorption performance, following pseudo‐second‐order kinetics and showing strong pH dependence. High selectivity (>97%) was obtained. Moreover, effective desorption and good reusability were observed, with only a slight decline in adsorption efficiency after 10 cycles. Continuous adsorption experiments conducted in a packed column revealed good agreement with the Thomas model, yielding breakthrough capacities of 86.22 and 78.18 mg g −1 for RR120 and MB, respectively.