Heterogeneous Photo-Fenton Catalytic Oxidation of Ciprofloxacin Using LaFeO3/Diatomite Composite Photocatalysts under Visible Light

摘要

LaFeO3/Diatomite porous disk composites have been successfully prepared by sol-gel method for the photocatalytic oxidative degradation of ciprofloxacin(CIP)compounds.The structure of the porous disc plays an important role in improving the photocatalytic activity by increasing the contact area between the photocatalyst and CIP to enhance CIP molecule adsorption.Meanwhile,the porous disk composite photocatalysts can effectively prevent the recombination of light-induced electron-hole pairs.A photo-Fenton-like reaction is triggered by addition of H2O2,which further remarkably improves the photocatalytic activity of LaFeO3/Diatomite.Then,the factors like catalyst concentration,H2O2 dosage,initial pH and CIP concentration of the solution responsible for the enhanced photocatalytic performance of the reaction system are investigated.The optimal degradation rate of ciprofloxacin by the LaFeO3/Diatomite catalyst is 99.02% after visible light irradiation for 150 min,which is 1.22 times of the pure LaFeO3.The catalysts have a much high stability which can be recycled for many times and the degradation rate of four cycles is still about 98%.The excellent performance and high photocatalytic efficiency of the LaFeO3/Diatomite photocatalyst make it have potential application foreground in the treatment of pharmaceutical wastewater.