Engineering oxygen vacancies and morphology of BiOCl microspheres via electrification to enhance visible light photocatalytic performance

Enhancing the separation efficiency of photo-generated carriers and the surface area of catalysts is beneficial to improve the photocatalytic performance, which is critical to achieving application of photocatalysis in practical environmental remediation. In this work, the BiOCl microspheres were treated with electrification for the first time to synergistically tune oxygen vacancies (OVs) and microstructure. With 6 h electrification, the photocatalytic performance of BiOCl-6 microspheres was significantly enhanced, which can not only degrade organic contaminants, 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, respectively, which were 5.1, 7.0 and 8.1 times higher than that of pristine BiOCl. The density functional theory (DFT) calculations and experimental investigation suggest that the designed OVs facilitates the separation of photo-excited carriers and expands the light adsorption range of BiOCl. Meanwhile, the increased surface area of BiOCl-6 microspheres enhances the adsorption for contaminants 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.