Metformin (MET) is an oral anti-glucose medication, which can not be removed effectively by traditional wastewater treatment technology. Herein, we fabricated for the first time highly active Z-scheme heterogeneous photocatalysts Z-Nb-X by combining Co-ZIF-67 derived Co₃O₄ skeleton material with Lindqvist type PONb (K₇HNb₆O₁₉) during a simple solvothermal. The obtained Z-scheme photocatalysts can significantly remove emerging contaminant metformin from effluent with an optimal removal efficiency of 63.8% within 7 min over the sample Z-Nb-0.8, which exhibits superior performance in comparison with photocatalytic systems reported, and has good stability and recoverability. The highly boosted photocatalytic degradation efficiency is attributed to a Z-scheme heterojunction constructed and hierarchical peony flower-like structure, which not only improved the photogenerated interfacial charge transfer but also greatly restrained electron-hole recombination. For MET removal process, three possible degradation pathways were unraveled according to the identification of intermediates. Additionally, the toxicity evaluation of intermediates was investigated, which shows that our prepared composites can reduce the toxicity of MET through the photocatalytic route. This work affords a new idea for the development of highly efficient and recyclable photocatalysts, which may be helpful to the extended application of POM-based composites in the environmental remediation of wastewater.

二甲双胍(MET)是一种口服降糖药，传统的废水处理技术无法有效去除。在此，我们首次通过将 Co-ZIF-67 衍生的 Co ₃ O ₄骨架材料与 Lindqvist 型 PONb (K ₇ HNb ₆ O ₁₉）在简单的溶剂热过程中。所获得的 Z-方案光催化剂可以显着去除废水中新出现的污染物二甲双胍，与样品 Z-Nb-0.8 相比，7 分钟内的最佳去除效率为 63.8%，与已报道的光催化系统相比表现出更优越的性能，并且具有良好的稳定性和稳定性。可恢复性。高度提高的光催化降解效率归因于构建的 Z 型异质结和分级牡丹花状结构，这不仅改善了光生界面电荷转移，而且极大地抑制了电子-空穴复合。对于 MET 去除过程，根据中间体的鉴定揭示了三种可能的降解途径。此外，还研究了中间体的毒性评估，这表明我们制备的复合材料可以通过光催化途径降低 MET 的毒性。该工作为开发高效、可回收的光催化剂提供了新思路，可能有助于POM基复合材料在废水环境修复中的推广应用。