In-situ synthesis of flower-like BiOBr/NaCo2O4 nanocomposite with enhanced visible-light photocatalytic activity

A novel flower-like photocatalyst BiOBr/NaCo 2 O 4 nanocomposite was successfully synthesized via a simple hydrothermal method . The as-obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), Electron spin response (ESR), N 2 adsorption-desorption measurements and UV–vis diffuse reflectance spectroscopy (UV–vis DRS), respectively. The results showed that BiOBr/NaCo 2 O 4 nanocomposite possessed enhanced photocatalytic activity for the removal of Rhodamine B (RhB) and colorless tetracycline hydrochloride (TC) under visible-light irradiation as compared with pure BiOBr and NaCo 2 O 4 . Moreover, coupling with NaCo 2 O 4 was concluded to broaden the absorption of visible-light irradiation and inhibit the recombination of the electron-hole pairs on the interface between BiOBr and NaCo 2 O 4 , which enhanced the activity of the photocatalyst. In addition, the narrower energy bandgap of BiOBr/NaCo 2 O 4 nanocomposite makes a contribution to the enhancement of photocatalytic performance. Based on the radical-trapping experiments, a possible photocatalytic mechanism has been proposed.