Atomically Thin Bi₂MoO₆ Nanosheets for Efficient Visible-Light Photocatalytic Nitrogen Fixation via O-Vacancy Tailored Exposure of Mo Sites

Efficient charge transfer and exposure of reactive sites represent critical factors in the enhancement of photocatalytic nitrogen fixation. Herein, an atomic-thickness phosphate-doped Bi2MoO6 photocatalyst was fabricated successfully. The introduction of PO43– doping induced lattice distortions within the Mo–O octahedron, resulting in the generation of oxygen vacancies and exposure of Mo sites that served as active centers for nitrogen activation. Additionally, the incorporation of PO43– dopants led to a reduced surface work function of Bi2MoO6, thereby effectively facilitating carrier migration. Furthermore, there is a notable reduction in carrier transport distance from the bulk to its surface due to the atomic sheet structure. As a consequence, the PO43–-doped Bi2MoO6 exhibited a significantly enhanced photocatalytic nitrogen fixation activity compared to the undoped sample. Moreover, PO43–-doped Bi2MoO6 showed improved photocatalytic performance for the reduction of Cr(VI). This work offers valuable theoretical insights for the development of highly efficient photocatalysts.