Photocatalytic properties of zirconium oxide–zinc oxide nanoparticles synthesised using microwave irradiation

ZrO2–ZnO nanoparticles with different mass concentrations of ZrO2 (1%, 5%, 10%, 20%) were prepared using a two-stage precipitation method with microwave irradiation. The ZrO2–ZnO with 10% of ZrO2 had the highest photocatalytic activity. The obtained material was characterised using XRD, which confirmed a high crystal structure in the synthesised material, and transmission electron microscopy (TEM) analysis, which depicted that micro and nano needle-shaped particles had been obtained and that irregularly shaped nanoparticles were present on the surface of those particles. TEM–EDX analysis confirmed the presence of both ZnO and ZrO2 in the product. FT-IR analyses showed that the positions of peaks related to Zn–O and Zr–O absorption bands did not change in ZrO2–ZnO NPs. The initial concentration of Methylene Blue (MB), the pH of the solution, and the mass of the photocatalyst were investigated to determine the photocatalytic efficiency of the material and the degree of removal of the MB. The highest efficiency (97%) was obtained in the following conditions: 30 mg/dm3 of the MB solution, pH 9 and 70 mg ZrO2–ZnO after 30 min of reaction time under UV irradiation.