Zeolite 13X particles with porous TiO2 coating and Ag2O nanoparticles as multi-functional filler materials for face masks

Abstract

Adsorbent components in face masks are crucial for protecting individuals exposed to dangerous situations. In this study, one porous TiO₂ layer was deposited on zeolite 13X particles by coating hybrid organic/inorganic titanium alkoxide film via molecular layer deposition (MLD), followed by heat treatment to remove organic components in the MLD film. Various concentrations of Ag₂O nanoparticles were impregnated on the TiO₂-coated 13X particles, offering a wide range of antibacterial, antifungal, and antiviral characteristics. The obtained composite particles were characterized using X-ray photoelectron spectroscopy and thermal gravimetric analysis to study the composition and mass loading of the organic components. The surface area and pore size distribution of the samples as well as the acid sites were determined using nitrogen adsorption/desorption and temperature programmed desorption of ammonia, respectively. The composite particles were evaluated for gaseous NH₃ adsorption in a continuous flow packed-bed column. The results showed a significant increase in NH₃ adsorption capacity from 25.2 mg/g in 13X to 45.9 mg/g in 10-13X (13X coated with 10 MLD cycles of titanium alkoxide followed by heat treatment in air) at 20 °C, while 10-13X still exhibited 31.0 mg/g of NH₃ adsorption capacity at 60 °C. In addition, carbon-doped 10-13X obtained by heat treatment of MLD coated sample under argon atmosphere increased the NH₃ adsorption capacity to 54.1 mg/g. The antibacterial testing against E.coli showed that samples with lower loadings of Ag₂O showed excellent antibacterial activity, demonstrating the strong antibacterial properties of the composites. Our findings showcase the potential of TiO₂-coated zeolite 13X particles as a novel multi-functional filler to enhance human safety in toxic environments and provide biological protection