Development of Nb2O5-doped ZnO/Carbon xerogel photocatalyst for the photodegradation of 4-chlorophenol

This work evaluates the properties of a new Nb2O5-doped ZnO/carbon xerogel photocatalyst and its efficiency for the degradation of 4-chlorophenol under solar radiation. The development of this material is aimed at diminishing charge recombination during the photocatalytic process. The diffractograms obtained confirm the presence of the hexagonal zinc oxide structure in all samples, whereas the X-ray photoelectron spectroscopy confirms the presence of Nb2O5 on the structure of the ternary photocatalyst. The higher specific surface area of the Nb2O5-doped material, as well as the lower value of gap energy, can be ascribed to the presence of the newly incorporated metallic oxide into the structure of the materials, along with the carbon xerogel. The photocatalytic tests results show that the material with Nb2O5 in its composition exhibited superior efficiency in the degradation of 4-chlorophenol under simulated solar radiation, obtaining a much higher apparent reaction rate constant. Furthermore, the modification impacts the photocatalytic mechanism, which becomes greatly dependent on the hydroxyl radical.