Degradation performance study and application of LED light-driven g-C3N4/ZnO composites

In this paper, first-principle calculations based on density-functional theory (DFT) and plane-wave pseudopotential basis for g-C3N4/ZnO composites were carried out using Quantum Espresso (QE) code. The g-C3N4/ZnO composite photocatalytic materials were prepared by solid-phase calcination and characterized by XRD, SEM, and FT-IR. Photocatalytic degradation experiments were carried out under LED light irradiation, using the dye rhodamine B (RhB) and the antibiotic tetracycline hydrochloride (TC) as simulated degradation targets. The degradation performance of the composites was tested using the commercially available pesticide glyphosate. The removal of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) from water samples was tested using real sewage livestock wastewater. The photocatalytic degradation mechanism of the composites was explored by free radical trapping experiments. Finally, the MTT cytotoxicity test demonstrated that the g-C3N4/ZnO composite photocatalytic materials are non-cytotoxic and are expected to be used in wastewater treatment.