Highly photocatalytic electrospun Zr/Ag Co-doped titanium dioxide nanofibers for degradation of dye

Abstract

Photodegradation has attracted much attention in wastewater treatment owing to its nontoxicity, high efficiency, and mild reaction conditions. Recently, Zr/Ag co-doped titanium dioxide (TiO2) nanoparticles have been synthesized and showed high photocatalytic activity for dye, but these nanoparticles tend to aggregate together, leading to reduced catalytic sites, which is disadvantageous for their practical application. Therefore, Zr/Ag-co-doped TiO2 nanofibers were prepared using an electrospinning method. For comparison, TiO2 nanofibers and Zr-doped TiO2 nanofibers were also fabricated. The synthesized catalysts were characterized by X-ray diffraction, UV–visible absorption spectroscopy, diffuse reflectance spectroscopy, scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, zeta potentials, photoluminescence, and electrochemical impedance spectroscopy. Compared with TiO2 nanofibers and Zr-doped TiO2, Zr/Ag co-doped TiO2 nanofibers have significantly enhanced photocatalytic activity for Congo red owing to the synergetic effects of Zr, Ag, and Ti. The photodegradation of Congo red followed a pseudo-first-order kinetic model. The optimal Zr/Ag-co-doped TiO2 nanofibers with 2 wt% Ag and a mass ratio of ZrO2 to TiO2 of 1:9 exhibits the best photocatalytic activity and the corresponding kinetic constant of 0.0405 min−1 is 12 times higher than that of TiO2 nanofibers. This work will provide data and a technology base for the synthesis of future materials with high photocatalytic activity.