Enhancing the Photocatalytic Properties of ZrO2/ZnO Nanocomposite Supported on Montmorillonite Clay for Photodegradation of Congo Red

In this work, the Photo catalytic degradation of Congo red, as an azo dye, was investigated via a ZrO2/ZnO nanocomposite (NC) supported on montmorillonite (MMT) clay. The ZnO nanoparticles (NPs), and the ZrO2/ZnO, and ZrO2/ZnO/clay NCs were prepared by the sol-gel method under ultrasonic irradiation. The morphologies and particle sizes of the synthesized nanomaterials were characterized by field-emission scanning electron microscopy coupled with X-ray dispersive spectroscopy. The particle size of the ZnO NPs, and the ZrO2/ZnO, and ZrO2/ZnO/clay NCs are 55 nm, 65 nm, and 35 nm, respectively. Fourier transform infrared and X-ray diffraction (XRD) were employed to determine the purity, crystalline phase, and crystallite size of the prepared nanomaterials. The XRD data showed the hexagonal structure of the ZnO and the monoclinic structure of ZrO2. The results showed that ZrO2/ZnO/clay NC is superior in Photo catalytic activity and adsorption efficiency in Congo red degradation. The Photo catalytic property of ZnO/ZrO2/MMT (92%) was enhanced to compare the as-synthesized ZnO NPs and ZnO/ZrO2 NCs. The effect of photocatalyst dosage and initial concentration of Congo red and pH of the solution was investigated. The optimum values were 0.5 g/L of photocatalyst dosage, 10 ppm initial concentration of CR solution, and a pH of 7.0 in the photodegradation process.