Photocatalytic activation of persulfate for the synergistic degradation of pollutants has become a major research hotspot, but the activation effect is poor due to the problems of low catalyst carrier separation efficiency and insufficient active sites. In this study, direct Z-Scheme heterojunctions of MoO₂@CoFe LDHs were prepared by a simple hydrothermal method and a Co and Fe dual active site system was constructed to activate Na₂S₂O₈ (PS) for the synergistic degradation of tetracycline under visible light. The results showed that the synergistic degradation of tetracycline was 3.7 times and 2.7 times more efficient than the original heterojunction and PS, respectively. Combining material characterisation, photovoltaic performance tests and theoretical calculations revealed that the high efficiency is attributed to the formation of an internal electric field under the Z-Scheme heterostructure type generating effective electron-hole separation, with more photo-generated electrons converted into radicals acting together with holes to degrade the TC and activate the PS. More importantly, Co(II) and Fe(II) provide electrons to synergistically activate PS, and a portion of the photogenerated electrons and PS activation intermediates can facilitate cycling between Co(II)/Co(III) and Fe(II)/Fe(III) to accelerate PS activation. This paper's work on activating PS-assisted Z-Scheme heterojunctions for the efficient degradation of TC provides a reference for the study of high-performance photocatalytic catalysts for the degradation of organic pollutants.

光催化活化过硫酸盐协同降解污染物已成为主要研究热点，但由于存在催化剂载体分离效率低、活性位点不足等问题，活化效果较差。在这项研究中，通过简单的水热法制备了MoO ₂ @CoFe LDHs的直接Z型异质结，并构建了Co和Fe双活性位点体系以激活Na ₂ S ₂ O ₈(PS) 用于在可见光下协同降解四环素。结果表明，四环素的协同降解效率分别是原始异质结和PS的3.7倍和2.7倍。结合材料表征、光伏性能测试和理论计算表明，高效率归因于在 Z-Scheme 异质结构类型下形成内部电场，产生有效的电子空穴分离，更多的光生电子转化为自由基共同作用带有孔以降解 TC 并激活 PS。更重要的是，Co(II) 和 Fe(II) 提供电子以协同激活 PS，一部分光生电子和PS活化中间体可以促进Co(II)/Co(III)和Fe(II)/Fe(III)之间的循环，从而加速PS活化。该论文在激活PS-assisted Z-Scheme异质结以高效降解TC方面的工作为研究用于降解有机污染物的高性能光催化催化剂提供了参考。