One Stone, Three Birds: Mussel‐Inspired Fabrication of Polypropylene/ <scp> MnO ₂ </scp> Composite Nonwovens for Formaldehyde Removal, Antibacterial Activity, and Photothermal Conversion

ABSTRACT Formaldehyde (HCHO) is a well‐known source of indoor air pollution, and the removal of HCHO under room temperature has emerged as an important aspect of indoor air purification. In this study, the co‐deposition layer of polydopamine (PDA) and tannic acid was used as the interlayer for the in situ growth of manganese dioxide (MnO 2 ) on PP needle‐punched nonwovens. The effects of concentration and pH of the KMnO 4 solution on the structure and performances of the PP/MnO 2 composite nonwovens were characterized using SEM, FTIR, SEM, XPS, TG, XRD, etc. The results showed that the optimal PP/MnO 2 composite nonwovens can be prepared at a KMnO 4 concentration of 0.09 mol·L −1 and a pH of 5.5 at 80°C. The PP/MnO 2 composite nonwovens exhibited effective HCHO removal performance at room temperature, achieving a removal efficiency of 47.9%. Additionally, the prepared PP/MnO 2 composite nonwovens exhibited excellent antibacterial properties and photothermal conversion capability. This work provides a new perspective on the use of nonwoven‐based materials to remove indoor air pollutants and has great potential in improving indoor air quality.