TiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action

Abstract Introduction: The industrial use of chemicals, including volatile organic compounds (VOCs), has led to increased air pollution, which poses health risks such as irritation and cancer. The adverse effects of these chemicals have necessitated an efficient control method. One method of mitigating these risks is through effective filtration of VOCs like formaldehyde. Nanofiber-based filtration, especially using nanomaterials, has been shown to improve pollutant removal efficiency. This study aims to add TiO₂/Ag₃PO₄ nano photocatalyst onto polyurethane fibers to increase formaldehyde removal efficiency. Materials and Methods The in situ deposition method was used to synthesize TiO₂/Ag₃PO₄ photocatalyst. The electrospinning method was used to synthesize polyurethane fibers containing photocatalysts. Various characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET surface area analysis, were employed to assess the materials. The efficiency of the synthesized substrates for formaldehyde removal was evaluated in a continuous reactor. Also, antibacterial properties were evaluated using the disk diffusion method against Escherichia coli and Staphylococcus aureus. Results XRD results confirmed the crystalline structure of the TiO2/Ag3PO4 composite, indicating a suitable method for its synthesis. SEM revealed that the TiO₂/Ag₃PO₄ nanoparticles had an average size of 102 nm, and the electrospun fiber diameters were around 450 nm. The formaldehyde removal efficiency was highest (86%) for the filter containing 1.5% TiO₂/Ag₃PO₄. Additionally, antibacterial tests showed inhibition zones against both bacterial strains, indicating significant antibacterial activity. Discussion and Conclusion: The TiO₂/Ag₃PO₄ composite exhibited excellent photocatalytic properties due to the presence of the anatase phase of TiO₂. The highest removal efficiency occurred with 1.5% TiO₂/Ag₃PO₄, with a decrease in efficiency at higher nanoparticle concentrations, likely due to particle aggregation and reduced surface area for pollutant interaction. The pure polyurethane substrate showed a 38% removal efficiency, suggesting its potential for VOC absorption. The photocatalytic mechanism involves the interaction between Ag₃PO₄ and TiO₂, which enhances pollutant degradation. The antibacterial properties of the composite were attributed to the generation of silver ions and oxygen radicals. Overall, TiO₂/Ag₃PO₄ nanofiber filters offer a promising solution for both pollutant removal and antimicrobial applications.