Enhancing photocatalytic CO₂reduction and biological activity using a silver nanoparticle-decorated ZnTiO₃/permutit composite

The development of efficient visible-light photocatalysts for CO₂ reduction and biological waste treatment is crucial yet challenging. This study presents silver-decorated oxygen vacancy-possessed zinc titanate (ZnTiO₃) nanoparticles loaded onto permutit (PT) zeolite using a simple two-step hydrothermal-precipitation method, forming a ternary construction. The Ag/ZnTiO₃/PT photocatalyst demonstrated exceptional photoreduction performance, converting CO₂ to CH₄ and CO at rates of 0.73 and 13.01 µmol g⁻¹ h⁻¹, respectively. The incorporation of metallic silver nanoparticles and oxygen vacancies significantly enhanced photocatalytic activity under visible light. Notably, the photocatalyst exhibited remarkable stability over 25 h of continuous CO₂ reduction reaction. Additionally, it effectively inactivated pathogenic bacteria, such as Pseudomonas aeruginosa and Staphylococcus aureus, with a minimum inhibitory concentration of 0.5 mg mL⁻¹, and showed potential as a disinfection agent for cancer cell waste treatment, inhibiting migration, colony formation, and proliferation of MDA-MB-231 cells within 48 h. This study provides valuable insights supporting the practical application of Ag/ZnTiO₃/PT in mitigating global warming and addressing environmental challenges caused by biological pollutants.