Fabrication of visible-light-driven Bi2O3-Bi3TaO7 nanocomposite for tetracycline degradation with enhanced photocatalytic efficiency

We have prepared a superfine powder Bi 3 TaO 7 which was attached in worm-like Bi 2 O 3 to form a Bi 2 O 3 -Bi 3 TaO 7 composite by a simple facile calcination method. The as-obtained samples were measured by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrum (EDX), Fourier transform infrared spectroscopy (FT-IR), UV–visible diffused reflectance spectrum (DRS) and X-ray photoelectron spectra (XPS). The optimal Bi 2 O 3 -Bi 3 TaO 7 (2.0Bi 2 O 3 :1.0Bi 3 TaO 7 ) sample show the highest photocatalytic efficiency for tetracycline (TC) degradation (90.06%) irradiated with visible light, compared with that of a bare Bi 3 TaO 7 catalyst. Meanwhile, radical capturing experiments indicate that the photo-induced holes (h + ) and hydroxyl radial (•OH) are the main active species. Through the measurement of photocurrent density and electrochemical impedance spectrum, it indicates that the photogenerated carriers are significantly separated due to the formation of heterojunctions . Consequently, the Bi 2 O 3 -Bi 3 TaO 7 photocatalyst may have potential applications in environmental purification.