Preparation Of ZnO/Co₃O₄ Hollow Microsphere By Pollen‐biological Template And Its Application In Photocatalytic Degradation

AbstractZnO/Co3O4 hollow microsphere was prepared by an impregnation method using lotus pollen as biotemplate for photocatalytic degradation of methylene blue (MB) and tetracycline (TC). This material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), UV‐Vis diffuse reflectance spectroscopy (UV‐Vis DRS), N2 physical adsorption and X‐ray photoelectron (XPS). The results show that it can replicate the spherical morphology of pollen and form a hollow microsphere after the calcination in air with the diameter of about 25 μm and the wall thickness of about 2 μm. Under the irradiation using a xenon lamp, the degradation rate of MB was 95% in 90 minutes, and the degradation rate of TC was 90% in 60 minutes. Compared with pure ZnO or Co3O4 microspheres prepared by the same method, the photocatalytic performance of ZnO/Co3O4 hollow microsphere is superior, because of synergistic effect between Co and Zn and enhanced electron transfer. In addition, ZnO/Co3O4 hollow microsphere exhibits high reusability without significant decrease of the degradation activities of MB and TC after four cycles.