In situ growth of defect-adjustable Bi₂WO₆/WO₃ heterojunction for efficient photocatalytic N₂ reduction

Herein, a strategy for the construction of defect-adjustable heterojunction photocatalysts with well-matched energy levels and tight binding is proposed. And defect-adjustable Bi₂WO₆/WO₃ heterojunction is prepared in situ by solvothermal method to improve the N₂ reduction performance. The results show that compared with the defect-free Bi₂WO₆/WO₃ heterojunction grown in water, the defective Bi₂WO₆ ultra-small nanosheets grown in glycol are tightly bound to WO₃ nanorods, increasing the contact area between the two and promoting the separation of photogenerated carriers. EPR results show that glycol has reducibility and effectively construct oxygen vacancy, which facilitates N₂ adsorption and activation. Meanwhile, the results show that S-scheme defective Bi₂WO₆/WO₃ heterostructure is formed, which results in higher NH₃ yield. The NH₃ yield of optimized Bi₂WO₆/WO₃ heterojunction is 73.4 μmol g⁻¹ h⁻¹, which is significantly higher than that of pure Bi₂WO₆ and WO₃. This work provides a new idea for the design of tightly bonded heterojunction photocatalyst.