In Situ Growth of Z-Scheme Co/Al-LDH@Co₃O₄@Co-F Heterojunctions with Interfacial Enhancement and Synergistic Effects on a Cobalt Foam Surface for Environmental Remediation Studies

Acomposite photocatalyst with interfacial enhancement andsynergistic effects was synthesized in situ on cobalt foam, and asimulated photocatalytic reactor was built to treat wastewater. Co/Al-LDHnanosheet clusters and Co3O4 nanowireswere successfully in situ grown on the surface of cobalt foam simultaneously.Co/Al-LDH nanosheet clusters enable multiple internal reflectionsof visible light, whereas Co3O4 nanowires actas a conductive network to accelerate electron transfer, and the twosynergize with each other to enhance the conversion efficiency oflight. Moreover, both of them can form a Z-scheme heterojunction structureand promote photocatalytic activity by surface oxygen vacancies andinterfacial enhancement effects. A removal rate of 98.7% for tetracycline(TC) and 71.2% for TOC can be achieved under visible light irradiationfor 120 min. The in situ growth of the active ingredient on the surfaceof Co-F can well maintain the structural and photocatalytic stabilityin a complex environment, allowing more than 10 cycles to be achieved.In addition, the simulated photocatalytic system enables efficientflow-through treatment of single or composite polluted water. After8 h of flow-through treatment for real pharmaceutical wastewater underreal sunlight, the COD and TOC removal rates reached to 67.8 and 56.2%,respectively. Ultimately, the comprehensive results of this studyconfirm the applicability of the simulated photocatalytic system forthe treatment of low concentration and high toxicity antibiotic wastewaterin the real environment.