Visible-light-driven g-C3N4/Cu2O heterostructures with efficient photocatalytic activities for tetracycline degradation and microbial inactivation

Abstract g-C3N4/Cu2O composites were successfully synthesized by a facile chemical precipitation method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and UV diffuse reflectance spectroscopy (UV-DRS) techniques were employed to characterize the as-synthesized photocatalysts. The photocatalytic experiments indicated that the g-C3N4/Cu2O composites displayed higher photodegradation activity of tetracycline (TC) and inactivation efficiencies of Escherichia coli (E. coli) as well as Fusarium graminearum (F. graminearum) in comparsion with bare g-C3N4 and Cu2O under visible light irradiation. Photoluminescence (PL) spectra implied that the heterojunction between g-C3N4 and Cu2O could efficiently promote the separation efficiency of photo-induced charge carriers. Active species trapping experiment and electron spin resonance (ESR) analysis revealed that O2−, OH and h+ played important roles in the photocatalytic process. This study could provide new insights into the design of multifunctional g-C3N4-based photocatalysts for environmental purification.