Enhancement photo-catalytic degradation of benzoic acid using the heterosystem NiCo2O4/ZnO

Abstract

The present work focused on the degradation of benzoic acid in aqueous solutions using the heterosystem NiCo2O4/ZnO as a semi-conductor. The material NiCo2O4 is prepared by a nitrate method and characterized by several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), reflectance diffuse (RD), electrical conductivity and the photo-electrochemical (PEC) characterizations. Under visible light, the benzoic acid degradation using a heterosystem NiCo2O4/ZnO is investigated. Several parameters are examined as the pH, the heterosystem ratio and the initial benzoic acid concentration. The results reveal that, as pH value increased from 2 to 6, the photo-degradation raised and the removal efficiencies attend the value 71%. The optimum results exhibited an enhancement photo-activity at a neutral pH and with a heterosystem ratio 50/50. The high efficiency is due to the present of unique structure constructed which increases the amount of electro-active sites and facilitates the electrolyte penetration via the electron transfer. Thus, the kinetic analysis showed that the photo-degradation rates can be approximated to be pseudo-first order, according to the Langmuir–Hinshelwood kinetics model.