Ultrasonic-assisted preparation of ZrO2/g-C3N4 nanocomposites with high visible-light photocatalytic activity for degradation of 4-chlorophenol in water

Various methods including photocatalysis have been used for degradation and removal of phenolic compounds, which classified as hazardous materials in the environment. Nanomaterials exhibited significant advantages for photocatalytic degradation of phenolic compounds compared to the conventional oxidation approaches such as traditional biological and physical methods. In this study, zirconia (ZrO₂)/graphitic carbon nitride (g-C₃N₄) nanocomposites were successfully synthesized using ultrasonication method and used for photodegradation of 4-chlorophenol (4-CP) in water under visible light. The g-C₃N₄ nanosheets, ZrO₂ nanoparticles (NPs), and ZrO₂/g-C₃N₄ nanocomposite were characterized by N₂ adsorption, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), photoelectrochemical (PEC) measurements, and photoluminescence spectroscopy (PL). The incorporation of ZrO₂ NPs enhanced the surface area and light absorption capacity of pristine g-C₃N₄. The photocatalytic activity of ZrO₂/g-C₃N₄ nanocomposite sample was evaluated by the degradation of 4-CP in aqueous medium. Results exhibited an increase in photocatalytic activity of ZrO₂/g-C₃N₄ nanocomposite compared to unmodified ZrO₂ NPs and pristine g-C₃N₄. In addition, reusability experiment of ZrO₂/g-C₃N₄ nanocomposite for photo-catalytic degradation, as well as for 4-CP adsorption showed the ZrO₂/g-C₃N₄ nanocomposites can be effectively used for several cycles.