Templated fabrication of graphitic carbon nitride with ordered mesoporous nanostructures for high-efficient photocatalytic bacterial inactivation under visible light irradiation

Abstract

Biohazards are widely present in water, and a variety of waterborne diseases can be aroused by contaminated water. Therefore, the effective removal of biological hazards from water is necessary for the protection of human health. In this study, graphitic carbon nitride (g-C3N4) with ordered mesoporous nanostructures was successfully synthesized by a template method using SBA-15 as a hard template. The morphology, crystal structure, specific surface area, molecular structure, and light absorption properties of the as-prepared sample were characterized by TEM, XRD, BET, FT-IR, and UV-Vis DRS, respectively. The photocatalytic performance of the ordered mesoporous g-C3N4 was evaluated by the inactivation of Escherichia coli K-12 in water under visible light irradiation. Results showed that the bacterial inactivation efficiency can reach as high as 99% within 2 h of VL irradiation, which is 4 times higher than that of bulk g-C3N4. Moreover, the photocatalytic bacterial inactivation mechanism was revealed by a scavenging study, and the main active species in the photocatalytic inactivation process was found to be a photogenerated hole. This work will provide useful information for the development of new efficient g-C3N4-based materials for enhanced water disinfection applications by introducing ordered mesoporous nanostructures in a photocatalyst design and fabrication.