Preparation, characterization, and application of ZnO@SiO2 core-shell structured catalyst for photocatalytic degradation of phenol.

In the current study, ZnO@SiO2 core-shell structured catalyst was synthesized for photocatalytic degradation of phenol from aqueous samples. The synthesized catalyst was characterized by Fourier transform infrared spectra, X-ray diffraction, energy-dispersive X-ray spectroscopy, UV-Vis-NIR diffuse reflectance spectroscopy, transmission electron microscopy, BET surface area, zeta potential, and field emission scanning electron microscopy. The effect of catalyst loading, initial phenol concentration, pH, UV light intensity and weight ratio of ZnO/(SiO2 + ZnO) were studied towards photocatalytic degradation of phenol. Moreover, photocatalytic activities of bare ZnO and ZnO@SiO2 were compared. The results advocated that ZnO@SiO2 catalyst showed high photocatalytic performance for degradation of phenol (96 % after 120 min) at an initial pH of 5.9, catalyst loading of 0.5 g/L and initial phenol concentration of 25 mg/L. Increase in the weight ratio of ZnO/(SiO2 + ZnO) from 0.2 to 0.33 significantly enhanced the photodegradation of phenol from 84 to 94 %. It was also found that photocatalytic activity of ZnO@SiO2 was higher than bare ZnO nanoparticles. Graphical abstract ᅟ.