Synthesis of TiO2 Nanofiber-Nanoparticle Composite Catalyst and Its Photocatalytic Decolorization Performance of Reactive Black 5 Dye from Aqueous Solution.

In this study, synthesis of TiO₂ nanofiber-nanoparticle composite photocatalyst was carried out and its photocatalytic decolorization performance was investigated. TiO₂ nanofibers were developed by electrospinning. The TiO₂ nanoparticle films were prepared by dipping the glass substrates into a sol solution made by sol-gel method. The TiO₂ nanofiber-nanoparticle composite was immobilized on glass plates and annealed at 500 °C. The effects of pH and catalyst loading were studied during a photocatalytic decolorization experiment using simulated dyeing wastewater containing Reactive Black 5 (RB5). The photocatalytic decolorization performance with 60 min of UV-irradiation time using the TiO₂ nanofiber-nanoparticle composite was found to be higher (94.4%) than that of the TiO₂ nanofibers (75.5%) and the TiO₂ nanoparticle catalyst (74.1%). An alkaline condition and high catalyst loading were found to be preferable to achieve optimum photocatalytic decolorization of Reactive Black 5 (RB5). The TiO₂ nanofiber-nanoparticle composite could be recovered after reusing multiple times through re-annealing at a high temperature. TiO₂ nanofibers based on a composite catalyst that is strongly immobilized on glass plates enlarges the prospect of the photocatalytic method as a compact, practical and effective advanced treatment process for effluents from textile wastewater. [ABSTRACT FROM AUTHOR]