Multifunctional air filter with enhanced filtration, formaldehyde degradation, and antibacterial properties using PET, PDA, and RGO-TiO2

Abstract

Currently, most air filters, such as polyester (PET) fiber non-woven fabric, only have a single function of particulate filtration. However, the removal of substances harmful to human health, such as volatile organic compounds (VOCs) and bacteria, is becoming increasingly important in indoor air purification. Herein, based on the biomimetic surface functionalization properties of polydopamine (PDA) and the photocatalytic degradation of organic matter and the antibacterial effect of RGO (reduced graphene oxide)-TiO2, a multifunctional NWP2/PET-PDA-RGO-TiO2(P/PPRT) filter with a sandwich structure was prepared for formaldehyde degradation, aerosol filtration, and bactericidal operation. The P/PP2R0.05T20 maintains optimal performance of photocatalytic reaction kinetics and reaches a formaldehyde degradation rate of higher than 79 % within 300 min in the 7th cycle of usage. Compared with the base subtracts, P/PP2R0.05T20 has the highest filtration efficiency of 88.57–99.18 % for 0.3–10 µm particles, respectively, and has a filtration efficiency of higher than 74 % for 0.3 µm particles in the 7th cycles of usage. The quality factor of P/PP2R0.05T20 is improved significantly due to the sandwich structure. The effect of loaded particulate on the catalyst for photocatalytic degradation of formaldehyde was also studied. It was found that the photocatalytic formaldehyde degradation rate of P/PP2R0.05T20 is about 81.8 % within 300 min under different A2 particulate load content. In addition, P/PP2R0.05T20 has a bioaerosol removal rate of higher than 98 % against E. coli. This study provides a practical approach to preparing a multifunctional air filter with the performance of aerosol filtration, photocatalytic degradation of formaldehyde, and bactericidal function using PET non-woven fabric.