Cobalt oxide loaded graphitic carbon nitride as adsorptive photocatalyst for tetracycline removal from aqueous solution

The treatment of antibiotic-containing wastewater is of great importance due to the potential threats of antibiotics to human and the ecosystem. We reported the preparation of cobalt oxide loaded graphitic carbon nitride (CoO/g-C 3 N 4 ) by an impregnation-calcination method for tetracycline (TC) removal from aqueous solution. The developed CoO/g-C 3 N 4 exhibited high adsorption capacity and fast adsorption kinetic for TC due to the complexation of TC with surface loaded CoO. In particular, 7%CoO/g C 3 N 4 3 sample presented a maximum TC adsorption capacity of 391.4 mg g −1 . It was found that Langmuir and pseudo-second order kinetic models fitted TC adsorption process well. Further photocatalytic studies showed that CoO loaded g-C 3 N 4 was active for TC photodegradation , although the photocatalytic reaction rate constant was lower than that of native g-C 3 N 4 . CoO nanoparticles loading on g-C 3 N 4 played the major role of adsorption sites rather than cocatalyst for photocatalysis . We believe that the developed CoO/g-C 3 N 4 could be a potential adsorptive photocatalyst for antibiotic pollutants removal from wastewater.