Photocatalytic Degradation of Printing and Dyeing Wastewater by F-N/TiO2/AC and F-N/TiO2/MAC Composite Photocatalysts

Abstract

Abstract A fluorine/nitrogen-co-doped titania/activated carbon (F-N/TiO2/AC) composite has been prepared through an immersion–hydrothermal method. Magnetic activated carbon (MAC) has been prepared through a chemical coprecipitation method and used to assemble the analogous composite F-N/TiO2/MAC. The characterization results show that F-N/TiO2/MAC contains a certain amount of magnetic ferrous oxide material, and the presence of magnetic ferrous oxide material will not affect the crystalline shape of TiO2. F-N/TiO2/MAC is a weak magnetic material, and it could be conveniently recycled by applying a strong magnetic field. Methyl orange solution has been used as a target to assess the photocatalytic degradation and recycling performances of the composites. Results show that the adsorption of methyl orange on the photocatalysts follows a pseudo second-order kinetic model, and the adsorption rate of F-N/TiO2/AC is higher. In the photocatalytic degradation of methyl orange pseudo first-order reaction kinetics study, the k value of F-N/TiO2/MAC was 0.00497 min−1, which was higher than that of F-N/TiO2/AC. Even though the adsorption performance of F-N/TiO2/MAC is not as good as that of F-N/TiO2/AC, its photocatalytic degradation performance is superior. Overall, the two composite materials show roughly the same removal efficiencies for methyl orange, reaching 100 % for F-N/TiO2/AC and 98.9 % for F-N/TiO2/MAC. In terms of recycling performance, the magnetic property of F-N/TiO2/MAC makes it easier to recover from mixed solutions.