A comparative study about the influence of nitrogen doping and oxygen vacancies on the photocatalytic performance of ceria

Aimed to evaluate the influence of nitrogen doping on the photocatalytic performance of ceria, three ceria samples, including nitrogen doped, rich oxygen vacancies contained and contrastive ceria were prepared from the decomposition of CeCO3OH under varied atmospheres. The physico-chemical characterizations and photocatalytic properties towards methylene blue (MB) and tetracycline (TC) of the obtained ceria were comparatively discussed in detail. Nitrogen-doped CeO2 exhibited significantly superior photocatalytic activities compared to CeO2 with rich oxygen vacancies for MB and TC photodegradation, which is mainly attributed to the significantly enhanced separation of photo-generated carriers (e−/h+). Density Functional Theory (DFT) simulation suggests that the introduced impurity states of N-doped CeO2 advance the formation and separation of e−/h+. Moreover, the electrons are simultaneously excited from N 2p and O 2p, which further elevates the carrier concentration on the nitrogen-doped CeO2, and promotes the effect of e− during the photodegradation. The obtained results offer powerful evidences for the significant enhancement on photocatalytic performances of nitrogen doped CeO2.