Enhanced photocatalytic performance of heterostructure CNNS@Bi2WO6 photocatalysts towards degradation of organic pollution

The flower-structured CNNS@Bi2WO6 heterostructure photocatalsts with enhanced photocatalytic performance were successfully fabricated by facile in-situ hydrothermal method. Compared with the g-C3N4 nanosheets (CNNS) and pure Bi2WO6, the flower-structured CNNS@Bi2WO6 heterostructure photocatalysts exhibited better photocatalytic performance and photocatalytic stability for degradation of rhodamine B (RhB) and tetracycline (TC) under visible. The effects of different CNNS contents on the photocatalytic efficiency of the heterostructure photocatalysts have been investigated. The results show that the CNNS@Bi2WO6 heterostructure photocatalst with CNNS mass ratio of 7% presents the best photocatalytic performance. The photocatalytic activity enhancement should be attributed to the effective separation of photogenerated electron-hole pairs and the efficient visible-light utilization efficiency. Compared with CNNS, the absorption of CNNS@Bi2WO6 photocatalysts in the visible region has been greatly strengthened, with red-shift absorption edge by the UV–vis diffuse reflectance spectra (DRS). The connection between CNNS and Bi2WO6 was studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The scavenging experiments with different trapping agents demonstrates that the photogenerated h+ in the system can play the main role during the RhB degradation process. Subsequently, the possible mechanism of photocatalytic degradation over flower-structured CNNS@Bi2WO6 heterostructure photocatalysts has been proposed.