Photocatalytic degradation of Rhodamine B by TiO₂/ZnO nanofibers under visible light irradiation

Photocatalytic reduction of contaminants in wastewater or polluted water can be enhanced by finding a suitable catalyst with property that utilizes an extended light adsorption spectrum, reducing the recombination of electron-hole pairs, and casting the catalyst into a form with large surface-to-volume ratio to be in contact with the contaminants. Based on these objectives, Zndoped TiO2 nanoparticles with high photocatalytic activity were synthesized by the sol-gel assisted nozzle-less electrospinning technique followed by calcining the precursor Ti(OiPr)4/ZnAc/PVP nanofibers in air in the temperature range of 450-650o. The thermal decomposition behavior was studied by thermogravimetric analyser and differential scanning calorimeter (TGA-DSC), and the morphology and crystal structure were monitored by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). With the different concentration of zinc acetate in the precursor solution, the diameter of fibers ranged from 80- 130 nm. The photocatalytic degradation of rhodamine B dye under visible light irradiation was also studied. It is found that the photosensitized degradation activity can be optimized by doping an appropriate amount of Zn (0.30 wt. %). Hence, the enhanced photodegradation of dyes with a new photocatalyst nanofiber under visible irradiation can be realized, which can take better use of solar energy.