Simultaneously enhanced photocatalytic and antibacterial activities of TiO2/Ag composite nanofibers for wastewater purification

Abstract

High throughput of polyacylonitile (PAN)-based Ag/TiO2 composite nanofibers were prepared by using needleless electrospinning method. The morphology and crystallinity characterization revealed uniform and smooth nanofibers with an average diameter ranged from 160 to 260 nm. The enhanced photocatalytic activity of PAN/Ag/TiO2 compared with PAN/TiO2 nanofibers under visible light irradiation was linked with high interfacial charge transfer and low bandgap due to Ag entity. High photodegradation efficiency for methyl orange, rhodamine B and methylene blue were achieved as 99.5%, 92% and 99% respectively during the 4 h experiment. Effect of key parameters (i.e. pH, oxygen and Ag/TiO2 loading dosage) on photodegradation efficiency of dyes were also investigated. Active species trapping experiments demonstrated that •O2-and •OH were dominant active species in the photocatalytic degradation of dyes. These composite nanofibers have also exhibited excellent antibacterial activity, e.g. 95% of E. coli and 99% of S. aureus were killed in 2 h. Bifunctional nanofibers can be easily recovered from the aqueous solution as compared with the TiO2 nanoparticles. Moreover, the daily production rate of nanofibers has reached over 1.4 kg in the laboratory test, which is 60 times higher than that using the single needle electrospinning method. This production rate may be further optimized in the pilot scale studies. High productivity and strong catalytic properties of nanofibers propose their potential applications in environmental remediation for economically and eco-friendly wastewater and air treatment materials.

Synthesis of Electrospun PAN/TiO2/Ag Nanofibers Membrane As Potential Air Filtration Media with Photocatalytic Activity

“…The improvement in photocatalytic activity is also supported by various studies that demonstrate TiO 2 /Ag to have good photocatalytic activity under visible light. 7 , 23 , 33 , 38 − 40 …”

Electrospun Carbon Nanofibers from Biomass and Biomass Blends—Current Trends

“…As a result of their high porosity and permeability, as well as their small pore size, reliable filtration of the smallest and finest particles can be achieved [44,45]. Other applications of nanofiber mats as filters include optical and chemical sensors [46], energy storage [47], aerospace [48], nanocatalysis [49], protective clothing [50], transportation [51], water and air filters for biotechnological and industrial applications [52][53][54][55][56][57][58], filtering of dye particles from wastewater from the finishing industry [59] or filtering of smoke filtration and flavor retention [60]. Great research interest in recent years shows the use of biomass for the production of nanofibers from the biomass and natural biopolymers used as a precursor for carbon and carbon nanofibers to make the contribution to the ecological point of view and the extraction of raw materials from natural resources.…”

Multifunctional Membranes—A Versatile Approach for Emerging Pollutants Removal

“…Electrospinning parameters, including polymer solution properties, can be changed and controlled in order to obtain different nanofiber morphologies. Electrospun nanofibers are excellent candidates for use as membranes in water and wastewater treatment, including dye degradation [129][130][131][132], heavy metal ion adsorption [133][134][135], oily water separation [136,137], and microbial disinfection [130,138,139]. There are many types of materials, and these are briefly presented in Figure 3.…”