We report an in situ constructed Mo@MoO 3 Schottky junction and investigate its synergistic interaction with oxygen vacancies for efficient N 2 photoreduction, where the Schottky junction forms a charge transfer channel during the photocatalytic reaction. The oxygen vacancies, while capturing electrons to activate N 2 , together with the Mo element, expand the light absorption range of the catalyst, allowing more efficient transfer of excited electrons to the active site for nitrogen fixation. [Display omitted] • In-situ construction of Mo@MoO 3 Schottky junctions. • Photocatalytic nitrogen fixation by synergistic interaction of Schottky junctions and oxygen vacancies. • Nanosheets of Mo@MoO 3 are more conducive to the rapid transfer of photogenerated electrons in photocatalytic reactions. Defect engineering is a promising technique that can activate nitrogen by injecting electrons into the anti-bonding molecular orbital of nitrogen through anion vacancies. Moreover, compared to a single component, Schottky junctions can effectively overcome rapid electron recombination, thereby significantly enhancing photoelectron utilization efficiency. In this work, we prepared Mo modified MoO 3 nanosheets with abundant oxygen vacancies by a solvothermal method and investigated the effect of synergistic interactions between Schottky junctions and oxygen vacancies on the photocatalytic performance of N 2 reduction reaction (NRR). The photocatalytic nitrogen fixation performance of Mo@MoO 3 nanosheets (MoO 3 -6) reached 50.78 μmol·g−1·h−1 without any scavenger, which was about 3 times that of commercial MoO 3. The Schottky barrier creates a built-in electric field generating charge transfer channels during the photocatalytic reaction, while the oxygen vacancies trap electrons to activate N 2 , and together with Mo, broaden the light absorption range of the catalyst, facilitating more efficient transfer of excited electrons to the active site. The synergetic advantages of Schottky junctions and oxygen vacancies are exploited in advancing the photocatalytic effect, providing new opportunities and challenges for the development of metal oxide-based materials. [ABSTRACT FROM AUTHOR]