Visible Light Photocatalytic Functional TiO₂/PVDF Nanofibers for Dye Pollutant Degradation

The photodegradation of poly(vinylidene fluoride) (PVDF)/titanium oxide (TiO₂) nanofibers under visible light is described, something that has not been previously reported in the literature. Visible light photocatalytic electrospun PVDF/TiO₂ nanofiber webs with anatase TiO₂ concentration varying from 0% to 20% (0%, 1%, 3%, 5%, 10%, and 20%) are produced, and their ability to degrade a toxic pollutant, Rhodamine B (RhB), is studied. Photodegradation study using UV–vis spectroscopy on PVDF/TiO₂ nanofiber webs (with TiO₂ concentration of 20%) shows that 80% of RhB is degraded within 6 h at the wavelength of 546 nm, which clearly falls within the visible spectra. The color of RhB solvent catalyzed by PVDF/TiO₂ nanofiber webs gradually changes from red to orange, then to yellow, further to light yellow till colorless, which suggests the complete photodegradation of RhB under visible light. To estimate the rate of photodegradation, the reaction constant k is calculated. Based on the k value, PVDF/TiO₂ nanofiber webs with 20% TiO₂ concentration show the highest degradation rate compared to other PVDF/TiO₂ nanofiber webs and pure TiO₂ nanoparticles. This study proves the viability of TiO₂-based nanofibers to have catalytic capabilities under low-energy visible light.