Fabrication of PVA/Ag-TiO2 nanofiber mats for visible-light-active photocatalysis

Abstract

Visible-light-active nanomaterials for the photodegradation of organic compound in water were fabricated using facile techniques. In this work, anatase titanium dioxide (TiO2) nanoparticles (NPs) were coupled with plasma-reduced silver (Ag) to shift its sensitivity to visible light. The NPs were subsequently immobilized in electrospun poly(vinyl alcohol) (PVA). The PVA/Ag-TiO2 nanofiber mats (NFMs) were subjected to plasma etching to partially expose the embedded NPs and improve photosensitivity. The NFM sample exposed to oxygen plasma exhibited 51% removal of methylene blue in water under visible light irradiation. Compared to the untreated NFM sample, plasma treatment resulted to a 20% increase in dye removal efficiency. In addition, total organic carbon (TOC) analysis of fishpond wastewater using the NFMs under visible-light irradiation was conducted. With the NFMs, there was a 32% decrease in TOC concentration while in the absence of the catalyst, a 142% increase was measured. The results showed the effectivity of the catalysts to counter the biochemical reactions that took place in the actual wastewater samples. Moreover, the immobilization of visible-light-active Ag-TiO2 NPs in PVA would extend its service life as well as minimize its environmental risk, making the NFMs ideal for removing organic compounds in wastewater.