Efficient degradation of tetracycline over Co/La oriented on g-C3N4 with the outstanding oxygen activation property under visible light

Surface of g-C3N4 nanosheets was decorated with < 1 nm sized Co/La oxides by deposition and in-situ thermal polymerization to obtain Co/La@g-C3N4 composites. Results of photo-electrochemical and XPS showed Co/La were combined with N on g-C3N4 by non-covalent bonds, which facilitated the charge transfer and separation and the visible light absorption. The degradation ratio of tetracycline and the COD value of the solution were 100% and 19.2, respectively, for 80 min under visible light showing the degradation of tetracycline over 0.63 wt % Co/La@g-C3N4 was superior to the other photocatalyst might be because of the confinement effect between layers and the synergistic effect of Co, La, and g-C3N4. Also, we speculated about the photocatalytic degradation intermediate products and mechanism of tetracycline depending on the results of experiments and LC-MS. Therefore, Co/La@g-C3N4 could be applied in exploiting to effectively remove pharmaceutical pollutants from wastewater under sunlight.