Dependence of photocatalytic and antimicrobial activity of electrospun polymeric nanofiber composites on the positioning of Ag-TiO2 nanoparticles

Abstract

In this work, Ag-TiO2-embedded nanofiber composite (AT-in-NF) and Ag-TiO2-decorated nanofiber composite (AT-sur-NF) were comparatively studied to investigate the effect of the position of the silver-loaded titanium dioxide (Ag-TiO2) on the performance of nanofiber composites under visible light irradiation. AT-in-NF and AT-sur-NF were prepared by electrospinning and simultaneous electrospinning/electrospray process, respectively, and the compositions of the nanofiber composites were deliberately controlled to be the same with the exception of the Ag-TiO2 position. AT-sur-NF, in which the Ag-TiO2 was exposed on the nanofiber surface, showed better photo-induced self-cleaning behavior for methylene blue staining under visible light irradiation than AT-in-NF. AT-sur-NF also exhibited excellent bacterial growth inhibition for both Staphylococcus aureus (Gram-positive bacteria) and Klebsiella pneumoniae (Gram-negative bacteria) while AT-in-NF exhibited the bacterial growth inhibition for just K. pneumoniae. These results show that the presence of highly dispersed Ag-TiO2 on the nanofiber surface endows the nanofiber composite with superior photocatalytic and antimicrobial activities, and is useful for designing and optimizing the high performance nanofiber composites. (C) 2015 Elsevier Ltd. All rights reserved.