Defect Engineering Enhances the Charge Separation of CeO2 Nanorods toward Photocatalytic Methyl Blue Oxidation

Defect-rich photocatalytic materials with excellent charge transfer properties are very popular. Herein, Sm-doped CeO2 nanorods were annealed in a N-2 atmosphere to obtain the defective Sm-doped CeO2 photocatalysts (Vo-Sm-CeO2). The morphology and structure of Vo-Sm-CeO2 were systematically characterized. The Vo-Sm-CeO2 nanorods demonstrated an excellent photodegradation performance of methyl blue under visible light irradiation compared to CeO2 nanorods and Sm-CeO2. Reactive oxygen species including OH, center dot O-2(-), and h(+) were confirmed to play a pivotal role in the removal of pollutants via electron spin resonance spectroscopy. Doping Sm enhances the conductivity of CeO2 nanorods, benefiting photogenerated electrons being removed from the surface reactive sites, resulting in the superior performance.