Synthesis of ZnWO₄/NiWO₄ photocatalysts and their application in tetracycline hydrochloride degradation and antibacterial activities

Background: Water pollution poses health risks to humans and ecosystems, with long-term accumulation of tetracyclines causing toxicity, disrupting cartilage tissue, and drug resistance, while antibiotics affect plant hormones and microorganisms. Scientists are exploring high-performance materials for antibiotic degradation and antibiotic-resistant bacteria, using photocatalytic techniques as a cost-effective solution. Method: In this study, ZnWO₄/NiWO₄ composite-based photocatalysts with varying mass ratios (from 10 % to 30 %) were successfully synthesized using hydrothermal and high-temperature calcination. The photocatalytic activity of the ZnWO₄/NiWO₄ nanocomposite first increases as the mass of NiWO₄ increases and then declines progressively. Different techniques were used to characterize its morphological structure and optical characteristics. The photocatalytic activity of ZnWO₄/NiWO₄ was evaluated using tetracycline hydrochloride as a model pollutant. Significant findings: The study found that a 25 % ZnWO₄/NiWO₄ composite ratio yielded the highest photocatalytic activity. The degradation efficiency was enhanced to 90.7 % under exposing it to visible light for 2 h. This enhanced photocatalytic activity is attributed to the S-scheme heterojunction formed by ZnWO₄ and NiWO₄, which promotes the separation of charge carriers. Remarkably 1 h of testing under simulated solar irradiation demonstrated that 25 % ZnWO₄/NiWO₄ exhibited a strong antibacterial effect. Finally, this study will lead to a method for fabricating eco-friendly nanomaterials for environmental remediation and antibacterial activities.