The effect of C-doping on the properties and photocatalytic activity of ZrO2 prepared via sol-gel route

This work explored the synthesis and characterization of zirconium oxide/carbon xerogel composite, using the material as a photocatalyst in the photodegradation of methylene blue. The band gap energy of the samples was determined using diffuse reflectance spectroscopy. The crystallographic phase, morphology, elemental analysis, analysis of metal content and porosity of the samples was examined by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and infrared spectrometry, respectively. The methylene blue concentration was determined using a UV-vis spectrophotometer. The analysis results confirm the formation of zirconium oxide in its monoclinic crystal structure in the pure oxide. The composite presented amorphous structure. The zirconium oxide/carbon xerogel composite presented a higher radiation absorption, in all wavelengths tested. The results regarding the degradation of methylene blue confirm the existence of photocatalytic activity of the materials when submitted to the UVC wavelength. The XZrC composite presented considerably superior photocatalytic efficiency, when compared to the pure semiconductor, as the degradation obtained with the composite was 67% higher than the one obtained with the ZrO2.