Efficient photocatalytic degradation of 2,4-dinitrophenol over mesoporous Zr and Ce co-doped TiO2 under visible light

In the present study, zirconium and cerium co-doped mesoporous TiO2 photocatalysts were prepared by sol-gel technique using Pluronic P123 as the structure-directing agent. The prepared catalytic materials were characterized by X-ray diffraction, high-resolution transmission electron microscopy, N-2 sorption studies, diffuse reflectance UV-vis absorption spectroscopic analysis and X-ray photoelectron spectroscopy. Zirconium and cerium co-doping on TiO2 induces visible-light absorption and decreases the bandgap energy. Zirconium and cerium co-doped mesoporous titania exhibit a high surface area with a large pore diameter. The photocatalytic activity has been evaluated for the photodegradation of 2,4-dinitrophenol under visible light illumination. The optimum loading of Zr4+ and Ce4+ to TiO2 was found to be 0.5 wt.%. Ce4+ and Zr4+ active sites are good electron scavengers, which can easily trap the excited electrons and shift the electrons to the adsorbed oxygen molecules and therefore efficiently extending the lifetime of the electron-hole pair. Moreover, Zr4+/Ce4+-TiO2 showed excellent photocatalytic activity towards the degradation of 2,4-dinitrophenol under visible light irradiation due to the formation of a large quantity of (OH)-O-center dot and O-2(-center dot) radicals.