Enhanced photocatalytic activity of electrospun tio2/ag@sio2 inorganic composite nanofibers toward colored organic dye

Abstract

Inorganic composite nanofibers consisting of TiO2, metallic Ag, and SiO2 nanoparticles were prepared using electrospinning to enhance photocatalysis of a colored organic dye. Inorganic composite nanofibers have a high surface-area-to-mass ratio and are suitable for various applications in catalysis, sensors, and environmental remediation. In this study, TiO2 and metallic Ag nanoparticles were homogeneously embedded in a phenylsilsesquioxane matrix by mixing molecular precursors such as titanium diisopropoxide bis(acetylacetonate) and Ag-neodecanoante with phenyltrimethylsilane-based organically modified silica particles dissolved in dimethylformamide. Electrospinning transformed these precursor mixtures to hybrid composite nanofibers. Subsequent application of heat at 1000 °C converted the hybrid composite nanofibers to inorganic composite nanofibers. Metallic Ag nanoparticles were used in the design of the composite photocatalyst to enhance its photocatalytic activity by exploiting the band gap overlap between metallic Ag and semiconducting TiO2 particles. Inorganic composite nanofibers without having Ag nanoparticles were also prepared for comparison purposes using only Ti and Si precursors. Rhodamine B was selected to test the photocatalytic activities of both inorganic composite nanofibers, and ultraviolet (UV)- visible light spectroscopy was used to investigate the photocatalytic activities of the inorganic composite nanofibers. Under UV light, TiO2/Ag@SiO2 inorganic composite nanofibers were more efficient than TiO2@SiO2 inorganic composite nanofibers. X-ray diffraction, transmission electron microscopy–energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy confirmed the uniform distribution of TiO2 and Ag nanoparticles in the corresponding composite nanofibers.