Photocatalytic property of a Bi2O3 nanoparticle modified BiOCl composite with a nanolayered hierarchical structure synthesized by in situ reactions

A Bi2O3 nanoparticle modified BiOCl composite was synthesized by a solvothermal method combined with in situ reduction and oxidation in KBH4 and H2O2 solutions respectively. The thickness of a BiOCl nanosheet and the amount of Bi2O3 nanoparticle can be adjusted by changing the KBH4 concentration. The structure, morphology, elemental composition and optical absorption performance were characterized by using an X-ray diffraction diffractometer, a scanning electron microscope, a high resolution transmission electron microscope, an X-ray photoelectron spectroscope and a UV-Vis diffuse reflection spectroscope respectively. A nanolayered hierarchical structure of BiOCl was observed, and Bi2O3 nanoparticles were found to be evenly distributed on the surface/interface of the nanosheets. The photocatalytic activity of the composite was tested by the degradation of 40 mg L-1 methyl orange solution under UV light illumination. The Bi2O3/BiOCl composite prepared in a KBH4 concentration of 0.02 M achieved the highest photocatalytic rate of 95.7% in 8 min under UV light illumination with a kinetic constant of 0.3125 l min(-1). The photocatalytic mechanism of the composite has been discussed.