Z-type heterojunction degradation of tetracycline by 2D g-CN with 3D oxygen vacancy BiWO.

Photocatalytic degradation is a promising strategy for environmental remediation. Graphitic carbon nitride (g-CN) is the most extensively reported metal-free material. Hierarchical flower-shaped BiWO particles were obtained using a simple hydrothermal method, with petals of flower-like BiWO with oxygen vacancies (BiWO OVs) with controlled content successfully decorated on g-CN nanosheets. A novel Z-scheme 2D/3D heterojunction photocatalyst, g-CN/BiWO OV, was successfully prepared, with its composition and structure studied using a series of material characterization techniques. Compared to single g-CN and BiWO OVs, the g-CN/BiWO OVs exhibited improved photocatalytic activity for the degradation of tetracycline, with a degradation rate of more than 90%. Moreover, electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Mott-Schottky measurements suggest that a Z-scheme heterojunction formed between the g-CN nanosheets and BiWO OV floral forms and that the photoinduced electrons in BiWO OVs bind to holes in g-CN, thus enhancing the extraction and utilization of carriers under photoexcitation. Hence, this study presents an effective method for constructing 2D/3D heterojunctions for solar fuel conversion and photocatalytic water treatment.