Abstract:

The zinc oxide （ZnO） nanomaterials grafted with C-O functional groups were synthesized by sol-gel, co-precipitation and hydrothermal methods, respectively. The phase purity, organic functional groups and UV absorption capacity were characterized by X-ray powder diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and ultraviolet-visible spectrophotometry （UV-vis）. The photocatalytic activities of ZnO nanoparticles synthesized by the three methods were compared using tetracycline hydrochloride as the target of degradation. All the three preparation methods were successful to obtain the ZnO nanomaterials grafted with C-O functional groups. The results of FTIR showed that the samples had no organic functional groups except for C-O functional group. UV-vis diffuse reflectance spectra showed that the products had strong absorption ability to ultraviolet light and weak absorption ability to visible light and could degrade tetracycline hydrochloride. Photocatalytic experiments showed that the best pH value for degradation of tetracycline hydrochloride was 13, the best catalyst dosage was 1 g/L, and the best concentration of tetracycline hydrochloride was 20 mg/L. The impurity level of C-O functional group played an important role in the photocatalytic degradation of tetracycline hydrochloride.

Key words: ZnO, sol-gel method, co-precipitation method, hydrothermal method, photocatalysis