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

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 plasmareduced 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.