In-situ construction of Schottky junctions with synergistic interaction of oxygen vacancies in Mo@MoO3 nanosheets for efficient N2 photoreduction

Abstract

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 MoO3 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 N2 reduction reaction (NRR). The photocatalytic nitrogen fixation performance of Mo@MoO3 nanosheets (MoO3-6) reached 50.78 μmol·g−1·h−1 without any scavenger, which was about 3 times that of commercial MoO3. 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 N2, 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.