Direct hydrolysis synthesis of BiOI flowerlike hierarchical structures and it's photocatalytic activity under simulated sunlight irradiation

• Direct hydrolysis synthesis of BiOI flowerlike hierarchical structures
• The photocatalytic activity of BiOI is higher than that of P25 TiO2.
• Hole and O2− were the active species of BiOI.

BiOI flowerlike hierarchical structure was synthesized via direct hydrolysis from BiI3 and characterized by powder X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) spectra, and transmission electron microscopy (TEM). As-synthesized BiOI showed higher photocatalytic activity in aqueous RhB photodegradation system than P25 TiO2 under simulated sunlight irradiation. The trapping experiments of active species and electron spin resonance (ESR) experiment during the photocatalytic reaction showed that the photocatalytic degradation of organic pollutants in BiOI system proceeds through direct hole transfer and O2− rather than OH.