The establishment of heterojunctions between phase interfaces is an important strategy to enhance catalytic activity, but the behavior of charge transfer and exciton dissociation is unsharpness and significant. Here, a Van der Waals heterojunction (VDWH) of Mo₂C/Bi₄O₅Br₂ composite with oxygen vacancies (BM) was synthesized via a facile method. Various experimental results and density functional theory calculations demonstrated that the compact VDWH and unsaturated oxygen vacancy induced interfacial Mo-O bonds to modulate surface electronic structure. Consequently, the electron extracted from the exciton formed a strong internal electric field, which boosted the dissociation of the excitons and charge transfer via the electron transfer channel of the Mo-O bond. Therefore, the BM shows excellent CO₂ reduction performance (1277.4 µmol g⁻¹ h⁻¹) and stability without using sacrificial agents and cocatalysts, which is about 6 times of Mo₂C/Bi₄O₅Br₂. This work not only gives deep insights into charge separation in VWDH and oxygen vacancy but also provides an efficient photocatalyst for efficient green energy conversion.

在相界面之间建立异质结是提高催化活性的重要策略，但电荷转移和激子解离的行为不清晰且显着。_{这里，Mo 2} C/Bi ₄ O ₅ Br ₂的范德华异质结 (VDWH)通过简便的方法合成了具有氧空位（BM）的复合材料。各种实验结果和密度泛函理论计算表明，紧凑的 VDWH 和不饱和氧空位诱导界面 Mo-O 键调节表面电子结构。因此，从激子中提取的电子形成了强大的内部电场，促进了激子的解离和通过Mo-O键的电子转移通道的电荷转移。因此，BM在不使用牺牲剂和助催化剂的情况下表现出优异的CO ₂还原性能（1277.4 µmol g ^-1 h ^-1）和稳定性，约为Mo ₂ C/Bi ₄ O ₅ Br的6倍₂ . 这项工作不仅深入了解了 VWDH 和氧空位中的电荷分离，还为高效的绿色能源转换提供了一种高效的光催化剂。