Next-Generation Eco-Friendly Hybrid Air Purifier: Ag/TiO2/PLA Biofilm for Enhanced Bioaerosols Removal

Abstract

Indoor air pollution poses a significant public health risk, particularly in urban areas, where PM2.5 and airborne contaminants contribute to respiratory diseases. In Thailand, including Chonburi Province, PM2.5 levels frequently exceed safety thresholds, underscoring the urgent need for effective mitigation strategies. To address this challenge, we developed a hybrid air purification system incorporating a bioplastic-based photocatalytic film of polylactic acid (PLA) embedded with titanium dioxide (TiO<inf>2</inf>) nanoparticles. For optimization, PLA films were functionalized with varying TiO<inf>2</inf> concentrations and characterized using SEM, FTIR, TGDTA, and UV–Vis. spectroscopy. A 5 wt% TiO<inf>2</inf> loading was identified as optimal and further enhanced with silver (Ag) nanoparticles to boost photocatalytic efficiency. The Ag/TiO<inf>2</inf>/PLA biofilm was fabricated via a compound pellet formulation process followed by blown film extrusion. Various compositions, with and without Ag, were systematically evaluated for photocatalytic performance. The novel customized hybrid air purifier developed in this study is designed to enhance indoor air purification efficiency by integrating Ag/TiO<inf>2</inf>/PLA biofilms into a controlled oxidation system. The air purification efficacy of the developed biofilm was evaluated through a controlled study on Staphylococcus aureus (S. aureus) removal under different treatment conditions: control, adsorption, photolysis, and photocatalytic oxidation. The impact of light intensity on photocatalytic efficiency was also examined. The photocatalytic oxidation of S. aureus was subjected to the first-order kinetic evaluation through mathematical modeling. Results demonstrated that the Ag/TiO<inf>2</inf>/PLA biofilm significantly enhances indoor air purification, providing a sustainable, scalable, and energy-efficient solution for microbial decontamination and pollutant removal. This innovative approach outperforms conventional adsorption, adsorption and photocatalytic oxidation systems, offering a promising pathway for improved indoor air quality.