A ternary dual Z-scheme heterojunction photocatalyst composed of Ag₃PO₄, AgBr and g-C₃N₄ was prepared by a facile chemical deposition method. Scanning electron microscope equipped with energy-dispersive X-ray, X-ray diffraction, diffusive reflective spectrophotometry and X-ray photoelectron spectroscopy were carried out to characterize the morphology, element and structure properties of the photocatalysts. The photocatalytic activity was evaluated by the photoelectrochemical tests and the degradation of tetracycline (TC). The results indicated that the composite Ag₃PO₄/AgBr-20%g-C₃N₄ exhibited the best photocatalytic activity in terms of the photocurrent response and the degradation of TC under visible light irradiation. The degradation rate of TC over the ternary photocatalyst was 0.12 min^-1, which was 2.55 and 3.24 times faster than that over Ag₃PO₄/AgBr and Ag₃PO₄, respectively. During photocatalysis, metallic Ag could be formed and served as the electron transfer mediator to build the dual Z-scheme heterojunction by bridging the recombination of electrons and holes. By this manner, more efficient separation of photo-generated carriers and better redox ability could be obtained, consequently promoting the photocatalytic activity. Additionally, the trapping experiments verified that ∙O₂^– and h⁺ played prominent roles in the photocatalytic processes, while the impact of ∙OH on the removal efficiency was relatively small.

采用简便的化学沉积法制备了由Ag ₃ PO ₄，AgBr和gC ₃ N ₄组成的三元双Z型异质结光催化剂。进行了配备能量色散X射线，X射线衍射，扩散反射分光光度法和X射线光电子能谱的扫描电子显微镜，表征了光催化剂的形貌，元素和结构性质。通过光电化学测试和四环素（TC）的降解来评估光催化活性。结果表明，复合Ag ₃ PO ₄ / AgBr-20％gC ₃ N ₄在可见光照射下，就光电流响应和TC的降解而言，其表现出最佳的光催化活性。TC在三元光催化剂上的降解速率为0.12 min ^-1，比Ag ₃ PO ₄ / AgBr和Ag ₃ PO ₄的降解速率快2.55倍和3.24倍。， 分别。在光催化过程中，金属Ag可以形成并充当电子转移介质，通过桥接电子和空穴的复合来构建Z型双结异质结。通过这种方式，可以更有效地分离光生载流子和更好的氧化还原能力，因此提高了光催化活性。另外，捕集实验证实∙ö ₂ ^-和H ⁺在光催化工艺发挥突出的作用，而∙OH的对去除效率的影响相对较小。