Solvothermal synthesis and enhanced visible-light photocatalytic decontamination of bisphenol A (BPA) by g-C3N4/BiOBr heterojunctions

Graphite-like C3N4 hybridized BiOBr photocatalysts have been synthesized through an EG-assisted solvothermal process in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br). The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and photocurrent. The g-C3N4/BiOBr photocatalysts showed high efficiency for the degradation of bisphenol A (BPA) and rhodamine B (RhB) under visible light irradiation. The results assumed that a loading amount of g-C3N4 over BiOBr lead to an increase of the photocatalytic activity under visible light irradiation and showed much higher photocatalytic activity than that of pure BiOBr sample. The enhanced photocatalytic performance could be attributed to the high separation efficiency of the photogenerated electron–hole pairs. The trapping experiments of radicals showed that hole was the main reactive species for the photocatalytic degradation of RhB. A possible mechanism of g-C3N4/BiOBr on the enhancement of visible light performance was proposed.