Preparation of TiO2-graphitized carbon composite photocatalyst and their degradation properties for tetracycline antibiotics

To enhance the adsorption capacity to tetracycline antibiotics and the activity of TiO2 for photocatalysis and optical applications, modified graphitized carbon (GC) was fabricated by peanut shell and waste electrode graphite materials. Then graphitized carbon-doped TiO2 (TiO2-GC) was synthesized using the impregnation method. Characterization of structure and morphological were confirmed that the crystal structure of the TiO2 film on the GC was pure anatase phase. FTIR and XPS peaks clearly indicated the formation of the Ti-C-O valence bond, and the UV–vis DRS showed that the bandgap of TiO2 decreased to 2.67 eV. Electrochemical properties indicated the excellent photoelectric properties and the recombination rate of photogenerated electron-hole pairs became lower in the composite photocatalyst. The results of the photocatalytic degradation of tetracycline hydrochloride experiment showed that the composite photocatalyst had high adsorption and degradation ability for tetracycline (catalysts amount 0.7 g/L, 94.64% with visible lamp irradiation for 2 h) and the photodegradation process accorded with the first-order kinetic equation. TiO2-GC remained stable in five consecutive cycles, which proved its reusability. Furthermore, its excellent cost-effectiveness and strong photon absorption property, which makes it a promising candidate for tetracycline antibiotics effluent treatment in practical applications.