BiOCl-Bi12O17Cl2 nanocomposite with high visible-light photocatalytic activity prepared by an ultrasonic hydrothermal method for removing dye and pharmaceutical

A BiOCl-Bi12O17Cl2 nanocomposite with a high visible-light response and a low photoinduced electron-hole pair recombination rate was successfully synthesized using an ultrasonic-hydrothermal method. The texture, structure, optical, and photocatalytic properties of the composite were characterized. The results showed that the composite had a sheet flower-like structure with a large specific surface area. Ultraviolet-visible diffuse reflection spectra and photoluminescence spectra showed that the composite had an excellent visible-light response and a low recombination rate of photoinduced electron hole pairs. The photocatalytic property of the composite was evaluated by the removal efficiency of rhodamine B and ciprofloxacin under visible-light illumination. The composite's reaction rate constant of removing rhodamine B (/ciprofloxacin) was approximately 8.14 (/4.94), 42.63 (/11.91) and 64.66 (/36.07) times that of Bi12O17Cl2, P25, and BiOCl, respectively. Furthermore, the composite showed a wide applicable pH range and excellent reusability. Mechanism analysis showed that photogenerated holes played a dominant role and ·O2− also contributed to photocatalytic degradation. In summary, this study presents a high-efficiency photocatalyst for wastewater treatment.