Engineering Vacancy and Morphology of Biocl Microspheres Via Electrification to Enhance Photocatalytic Performance Under Visible Light

Abstract

Enhancing the separation efficiency of photo-generated carriers and the surface area of catalysts is conductive to improve of photocatalytic performance, which is critical to achieving application of photocatalysis in practical environmental remediation. In this work, the BiOCl microspheres for the first time were treated with electrification to synergistically tune oxygen vacancies (OVs) and microstructure. With 6 h electrification, the visible light catalytic activity of BiOCl-6 microspheres was significantly enhanced, which can not only degrade organic pollutants, but also effectively reduce toxic heavy metal ions. The photocatalytic reaction rates for methyl blue (MB), ciprofloxacin (CIP) and hexavalent chromium Cr(VI) reached 0.071, 0.056 and 0.097 min-1, which were respectively 5.1, 7.0 and 8.1 times than that of pristine BiOCl (p-BiOCl). The density functional theory (DFT) calculations and experimental investigation suggest that the designed OVs facilitate the separation of photo-excited carriers and extent light adsorption range of BiOCl. Meanwhile, the increased surface area of BiOCl-6 microspheres enhances the adsorption for organic pollutants and provides more active sites for photocatalytic reaction. This work provides a new approach to synergistically enhance photocatalytic performance for photocatalysts by vacancy engineering and morphology control.

Keywords: oxygen vacancy, Morphology, Photocatalysis, degradation, Visible light