Nickel ferrite/TiO₂ Nanofibrous Composite: Enhanced Photocatalytic Dye Degradation Under Visible Light

A highly efficient NiFe₂O₄/TiO₂ nanofibrous photocatalyst was prepared by a simultaneous solution blow spinning method. The hybrid fibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and magnetometry. The photocatalytic properties were evaluated using Crystal violet (CV) and Congo red (CR) dyes under visible light irradiation. Fibers calcined at 600 ºC and 700 ºC showed the highest CV decolorization (77%). On the other hand, for CR, the best performance was encountered with the photocatalysts heat-treated at 500 ºC, which exhibited photocatalytic degradation of 87% after only 30 min of visible light irradiation. The high reaction rates (0.018 to 0.067 min^-1) explain the fast decolorization yielded by the combined effect of adsorption and photocatalytic processes. Moreover, recyclability assays showed stable CR dye efficiency after five recycling cycles. Therefore, the NiFe₂O₄/TiO₂ nanofibers present a high potential for application in the decolorization treatment of wastewater from the textile industry.

Keywords:
Nickel ferrite/titania nanofibers; Congo red; Crystal violet; Photocatalysis