A 2D–2D BiO2−x/Bi2WO6 composite assembled via layer on layer and application in the abatement of the aqueous tetracycline

Tetracyclines (TCs) are one of the most common types of antibiotics. In this investigation, a 2D–2D BiO 2−x /Bi 2 WO 6 composite has been assembled via growing Bi 2 WO 6 in situ on the sheets of BiO 2−x by a simple hydrothermal process and has been applied to removal residual TCs in waterbody. The XRD , SEM, TEM , and XPS analyses reveal that BiO 2−x /Bi 2 WO 6 composite is a compact 2D–2D heterojunction and exhibit rich oxygen vacancy . Among the series of composites with the different ratios, 20BiO 2−x /Bi 2 WO 6 displays a more excellent visible-light photocatalytic performance with a 96.4% degradation rate of TC, compared to pure Bi 2 WO 6 (47.9%) and BiO 2−x (73.3%). The enhanced photodegraded mechanism is revealed in view of the XPS analysis, ESR spectra and density function theory (DFT) calculation. The excellent photocatalytic performance is attributed to the BiO 2−x /Bi 2 WO 6 heterojunction and the generation of more oxygen vacancies originated from the co-shared Bi species and redox couple Bi 5+ /Bi 3+ pairs in composite, which will increase the light trapping ability, accelerate the electron transfer , induce a strong redox, and lead to the excellent photo-degraded activity for aqueous TC. This research provides a new insight into the development of the novel bismuth base photocatalyst via growing in situ strategy in the application to photo-catalytically decompose aqueous antibiotic residues.