Facile sol-gel preparation of Cd-doped cerium oxide (CeO2) nanoparticles and their photocatalytic activities

Highlights: • Nanostructured Cd-doped CeO₂ is synthesized using the facile sol-gel process. • The structural studies reveal the cubic fluorite phase of Cd-doped CeO₂. • The spherical/elliptical shaped particles can be seen in the SEM and TEM studies. • The magnetic property of sample showed the ferromagnetic nature of CeO₂. • The photocatalytic degradation of Rhodamine B and Congo red dyes are investigated. Nanostructured Cd-doped cerium oxide (CeO₂) is synthesized using the facile sol-gel process. The structural studies such as powder XRD, FTIR and Raman reveal the cubic fluorite phase of Cd-doped CeO₂. The SEM and TEM analyzes interpret the spherical/elliptical morphology of the Cd-doped CeO₂ nanoparticles of sizes ranging between 7 and 8 nm. The ferromagnetic nature of Cd-CeO₂ is confirmed by magnetization hysteresis loop measurements at room temperature. The Cd-CeO₂ samples show a strong absorption below 400 nm, which is much blue-shifted towards a shorter wavelength, indicating a narrow and uniform particle size distribution. From the PL studies, an intense green emission band is located at 530 nm due to the transition from the Cd donor level to the oxygen vacancies level traced in the CeO₂ band gap. The photocatalytic degradation of Rhodamine B and Congo red dyes in aqueous solution under UV irradiation in the presence of Cd²⁺ and Pd²⁺ doped CeO₂ samples are investigated on a comparative study. The high photocatalytic activity authenticates that Cd-CeO₂ nanomaterials are a kind of promising photocatalysts in remediation of water polluted by some chemically stable organic dyes.