A superfine glass fibre air filter with rapid response to photocatalytic antibacterial properties under visible light by loading rGO/ZnO

ZnO-PLLA/PLLA Preparation and Application in Air Filtration by Electrospinning Technology

With the increasing environmental pollution caused by disposable masks, it is crucial to develop new degradable filtration materials for medical masks. ZnO-PLLA/PLLA (L-lactide) copolymers prepared from nano ZnO and L-lactide were used to prepare fiber films for air filtration by electrospinning technology. Structural characterization of ZnO-PLLA by H-NMR, XPS, and XRD demonstrated that ZnO was successfully grafted onto PLLA. An L₉(4³) standard orthogonal array was employed to evaluate the effects of the ZnO-PLLA concentration, ZnO-PLLA/PLLA content, DCM(dichloromethane) to DMF(N,N-dimethylformamide) ratio, and spinning time on the air filtration capacity of ZnO-PLLA/PLLA nanofiber films. It is noteworthy that the introduction of ZnO is important for the enhancement of the quality factor (QF). The optimal group obtained was sample No. 7, where the QF was 0.1403 Pa^-1, the particle filtration efficiency (PFE) was 98.3%, the bacteria filtration efficiency (BFE) was 98.42%, and the airflow resistance (Δp) was 29.2 Pa. Therefore, the as-prepared ZnO-PLLA/PLLA film has potential for the development of degradable masks.

A superfine glass fibre air filter with rapid response to photocatalytic antibacterial properties under visible light by loading rGO/ZnO

The development of high-performance air filter has become more and more important to public health. However, it has always been very challenging for developing a multifunctional air filter to simultaneously achieve excellent filtration and antibacterial properties. Herein, a versatile air filter was prepared with loading the reduced graphene (rGO) and zinc oxide on the superfine glass fibre (s-GF) with the three-dimensional network structure by in situ sol-gel process followed by calcination, which aims to achieve synergistic high-efficiency air filtration and rapid response to photocatalytic antibacterial properties under visible light. The air filter showed a three-dimensional network structure based on a rGO/ZnO/s-GF multilayer and exhibited the highest catalytic performance by achieving a 95% degradation effect on rhodamine B within 2 h and achieving 100% antibacterial inactivation of the Escherichia coli and Staphylococcus aureus within 4 h under visible light when the weight ratio of rGO in rGO/ZnO is 1.6%. The air filtration efficiency can also be maintained at 99% after loading ZnO and rGO photocatalytic particles. The spectrum of the photoluminescence (PL), UV-Vis diffuse reflectance spectra (DRS) and electron spin resonance (ESR) indicate that the combination of rGO and ZnO on the s-GF can increase the separation of photogenerated carriers and the specific surface area of the air filter, thereby increasing the photocatalytic response and antibacterial properties of the s-GF air filter under visible light in a short time.