Influence of yttrium doping on the photocatalytic activity of bismuth oxybromide for ciprofloxacin degradation using indoor fluorescent light illumination

In this work, a series of Y-doped BiOBr photocatalysts with different yttrium contents were successfully synthesized through a facile ethylene glycol-assisted chemical precipitation method for the first time. The as-synthesized photocatalysts were characterized using N-2 physical adsorption, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope accompanied with an energy-dispersive X-ray spectroscopy (FESEM/EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), photoluminescence (PL) and UV-Vis diffuse reflectance spectra (UV-Vis/DRS). Doping of Y3+ ion had no obvious effect on the structure and morphology of BiOBr, however the BET surface area was greatly improved. The photocatalytic degradation of ciprofloxacin under indoor fluorescent light illumination showed that doping of Y3+ ion could bring about a significant increase in the photocatalytic activity. Among the doped samples, the 3%Y-BiOBr showed the highest photocatalytic activity for 20 ppm ciprofloxacin with degradation efficiency of 87.6% in just 60 min as compared to pristine BiOBr which had the degradation efficiency of 71.7%. Such enhanced photocatalytic activity could be attributed to the efficient separation of photogenerated electron-hole pairs, increased optical absorption and high surface area. A possible mechanism for the photocatalytic reaction has been proposed.