Abstract: CeO₂-ZrO₂ solid solution is generally synthesized through chemical precipitation, followed by high-temperature calcination. The grains of solid solution under high-temperature calcination are prone to aggregate and grow, resulting in lower specific surface area and weaker adsorption and catalytic performance. In this study, nanocrystalline CeO₂-ZrO₂ solid solutions were prepared by a simple one-step alcohothermal method, avoiding effects of high-temperature calcination on grain growth and specific surface area reduction. The crystal structure, morphologies and thermal stability of the synthesized CeO₂-ZrO₂ solid solution were characterized by different techniques, and arsenic removal performance was tested. The results show that nanocrystalline CeO₂-ZrO₂ solid solutions have complete grain growth with large specific surface areas, high particle purity and good dispersibility, improving adsorption effect on As (III) in water. The arsenic adsorption results show that maximum adsorption capacity of Ce_0.8Zr_0.2O₂ sample can reach 160 mg/g at a As(III) equilibrium solubility of 100 mg/L, which is much higher than pure CeO₂ and ZrO₂ samples, as well as CeO₂-ZrO₂ solid solution prepared by traditional calcination method. In addition, the prepared Ce_0.8Zr_0.2O₂ solid solution maintains a high As (III) removal rate and good acid-alkali resistance within pH range of 3-9. The arsenic adsorption mechanisms indicate that As (III) ions in the solution form coordination bonds with metal ions on the surface of Ce_0.8Zr_0.2O₂ solid solution, which belongs to the chemical adsorption process.

Key words: alcohothemal, CeO₂-ZrO₂ solid solution, arsenic removal performance, adsorption mechanism