Design of photocatalysts with high-efficiency for sunlight utilization is one of the prerequisites for CO₂ photoreduction. Besides, modulating a stable electron-donating environment to meet the energy barrier for CO₂ reduction to CO is crucial. In this work, the ZnSe/Ag₂Se/AgBr (ZAA) heterojunction was fabricated by growing the ZnSe on the AgBr surface accompanied by in-situ generation of Ag₂Se between the two components by hydrothermal process. Results showed that the ZAA exhibited excellent light response ability over the full wavelength range. X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) demonstrated that the charge transfer of the ZAA conformed to dual Z-scheme mechanism, with the Ag₂Se acting as an electron transfer bridge, which in turn acted as an electron reservoir to accelerate electron transfer, facilitating carriers’ separation. The highest CO yield of 54.14 µmol/g/h was obtained from the optimal ZAA-2, which was 11.76 and 10.44 times of pure ZnSe and Ag₂Se, respectively. This work demonstrated the feasibility of a dual Z-scheme heterostructure with full spectrum response for offering stable electron-donating environment and improving electron transfer for enhanced photocatalytic activity.

设计高效利用阳光的光催化剂是CO ₂光还原的前提之一。此外，调节稳定的供电子环境以满足将 CO ₂还原为 CO 的能垒至关重要。在这项工作中，ZnSe/Ag ₂ Se/AgBr (ZAA) 异质结是通过在 AgBr 表面上生长 ZnSe 并通过水热过程在两种组分之间原位生成 Ag _{2 Se 来制造的。}结果表明，ZAA 在整个波长范围内表现出出色的光响应能力。X射线光电子能谱（XPS）和电子自旋共振（ESR）表明ZAA的电荷转移符合双Z型机制，Ag ₂Se作为电子转移桥，反过来又作为电子库加速电子转移，促进载流子分离。最佳ZAA-2获得了54.14 µmol/g/h的最高CO产率，分别是纯ZnSe和Ag ₂ Se的11.76和10.44倍。这项工作证明了具有全光谱响应的双 Z 型异质结构在提供稳定的供电子环境和改善电子转移以增强光催化活性方面的可行性。