Fabrication and photocatalytic performances of BiOCl nanosheets modified with ultrafine Bi2O3 nanocrystals

Abstract

BiOCl nanosheets modified with ultrafine Bi₂O₃ nanocrystals were synthesized by chemical deposition with the assistance of ascorbic acid and Pluronic F127. The structure, morphology, elemental composition and optical absorption performance were characterized using X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffuse reflection spectroscopy, respectively. Square-like BiOCl nanosheets with ultrafine Bi₂O₃ nanocrystals evenly distributed on the surface were obtained. The photocatalytic activity of the composite was tested by degrading a 40 mg L⁻¹ methyl orange solution under UV light illumination. A Bi₂O₃/BiOCl composite prepared with a Bi(NO₃)₃ concentration of 0.01 M achieved the highest photocatalytic rate of 100% in 6 min under UV light illumination. Repeated experiments on the degradation processes and recycling experiments on the photocatalysts were conducted under the same conditions. The results show that the as-synthesized Bi₂O₃/BiOCl composites possess excellent photocatalytic activity and outstanding recyclability. The photocatalytic mechanism of the composite is discussed.