Effect of the Oxygen Vacancies in CeO2 by the Ce3+ Incorporation to Enhance the Photocatalytic Mineralization of Phenol

• Published in: ChemistrySelect (Weinheim) Vol. 6; no. 14; pp. 3435 - 3443
• Main Authors: Méndez‐Salazar, Sandra, Aguilar‐Martínez, Octavio, Piña‐Pérez, Yanet, Pérez‐Hernández, Raúl, Santolalla‐Vargas, Carlos E., Gómez, Ricardo, Tzompantzi, Francisco
• Format: Journal Article
• Language: English
• Published: 15.04.2021
• Subjects: Ce3+-doped CeO2; environmental chemistry; photocatalysis; photooxidation; waste prevention
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202100459

In this paper, the phenol mineralization by Ce3+‐doped CeO2 by photocatalysis at room temperature, is shown for the first time. The photocatalytic behavior of CeO2 was improved through the incorporation of Ce3+ into its crystalline lattice. The materials were prepared by the precipitation method at low temperatures varying the Ce4+:Ce3+ molar ratio of the precursors during the synthesis process. It is worth noting that, the synthesized photocatalysts did not carry out a thermal treatment after their preparation. The results obtained from Raman analysis demonstrated the formation of oxygen vacancies by the incorporation of Ce3+. The improvement of the photocatalytic activity was attributed to an optimal content of Ce3+ which promoted structural defects (such as oxygen vacancies). Radical species, such as O2.−, are mainly formed during the photocatalytic process, which are probably the main responsible for inducing the mineralization process of the studied pollutant. The controlled insertion of oxygen vacancies within CeO2 promotes an increase in the photocatalytic activity for the mineralization of phenol in aqueous medium. The oxygen vacancies act as electron traps that retard the recombination of the photogenerated electron‐hole pair.