The photocatalytic nitrogen reduction offers a promising strategy for ammonia (NH₃) production, with the kinetics of the reaction depending on the transfer of photoinduced electrons to the adsorbed N₂ molecules. However, the energetic electrons may flow into the defect states of the photocatalyst, thereby impeding nitrogen fixation. Herein, were report a novel heterojunction photocatalyst system for photocatalytic NH₃ production, comprising BiO quantum dots (QDs) and nitrogen defective ultrathin carbon nitride (UCNx), which overcomes this limitation. Efficient spatial charge separation is achieved through nitrogen vacancies and the intimate heterojunction contact between the BiO QDs and UCNx. Benefitting from efficient charge separation, the adsorbed N₂ on nitrogen vacancies and Bi²⁺ sites can effectively receive energetic electrons and in turn boost NH₃ production. The optimal hybrid catalyst (BiCNx-5) shows excellent photocatalytic performance, with NH₃ production rate of 576.11 μmol g⁻¹ h⁻¹ under visible light illumination (λ > 420 nm). This study provides a platform for the future design of effective photocatalysts for NH₃ production.

光催化氮还原为氨（NH ₃）的生产提供了一种有希望的策略，反应的动力学取决于光致电子向吸附N ₂分子的转移。但是，高能电子可能流入光催化剂的缺陷状态，从而阻碍了固氮。本文报道了一种新颖的用于光催化生产NH _3的异质结光催化剂体系，该体系包含BiO量子点（QD）和氮缺陷超薄氮化碳（UCNx），克服了这一局限性。通过氮空位以及BiO QD和UCNx之间紧密的异质结接触，可以实现有效的空间电荷分离。得益于有效的电荷分离，吸附的氮氮空位上的₂和Bi ²⁺位点可以有效地接收高能电子，进而提高NH _3的产生。最佳的杂化催化剂（BiCNx-5）表现出优异的光催化性能，在可见光（λ> 420 nm）下，NH _3的生成率为576.11μmolg ^-1 h ^-1。这项研究为将来设计用于生产NH ₃的有效光催化剂提供了一个平台。