Photoexcitation assisted oxygen vacancy for enhancing N fixation was investigated with Fe-CeO as photocatalysts. Fe substituted doping of CeO promoted the formation of oxygen vacancies (Vo). 5 % Fe-CeO exhibited the highest Vo concentration with photocatalytic nitrogen fixation efficiency of 176 μmol·g·h. The oxygen vacancy could induce the formation of the oxygen vacancy level, which could reduce the band gap energy, attract electrons, and hinder the electron hole recombination. More importantly, the oxygen vacancy level could be used as a springboard to reduce the energy required for N activation. In addition, calcination and acid-wash were used to regulate the concentration of surface oxygen vacancies (Vo-s) and bulk oxygen vacancies (Vo-b), respectively. The results showed that acid-wash only reduced the Vo-s concentration, while calcination reduced both the Vo-s and the Vo-b concentration, and the high concentration of Vo and Vo-s was beneficial for photocatalytic nitrogen fixation. The regulation strategy of Vo had guiding significance for improving the photocatalytic performance of metal oxide photocatalysts.

中文翻译：

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光激发辅助氧空位增强 Fe-CeO2 固氮

以 Fe-CeO 作为光催化剂研究了光激发辅助氧空位增强固氮作用。 Fe取代CeO的掺杂促进了氧空位（Vo）的形成。 5 % Fe-CeO表现出最高的Vo浓度，光催化固氮效率为176 μmol·g·h。氧空位可以诱导氧空位能级的形成，从而降低带隙能，吸引电子，阻碍电子空穴复合。更重要的是，氧空位水平可以作为减少氮活化所需能量的跳板。此外，煅烧和酸洗分别用于调节表面氧空位（Vo-s）和本体氧空位（Vo-b）的浓度。结果表明，酸洗仅降低了Vo-s浓度，而煅烧则降低了Vo-s和Vo-b浓度，且高浓度的Vo和Vo-s有利于光催化固氮。 Vo的调控策略对于提高金属氧化物光催化剂的光催化性能具有指导意义。