Bi2WO6-BiOCl heterostructure with enhanced photocatalytic activity for efficient degradation of oxytetracycline.

The application of BiOCl in photocatalysis has been restricted by its low utilization of solar energy and fast recombination of charge carriers. In this study, zero-dimensional (0D) Bi2WO6 nanoparticles/two-dimensional (2D) layered BiOCl heterojunction composite was successfully constructed by facile hydrothermal and solvothermal methods. The most favorable sunlight photocatalytic activity was achieved for the as-prepared Bi2WO6-BiOCl composites with a ratio of 1%. The photocatalytic rate and mineralization efficiency of one typical antibiotic (i.e., oxytetracycline) over 1% Bi2WO6-BiOCl was about 2.7 and 5.3 times as high as that of BiOCl. Both experimental characterizations and density functional theory (DFT) calculations confirmed that the excellent photocatalytic performance mainly arised from the effective charge separation along the Bi2WO6 and BiOCl heterojunction interface. The effective electron transfer was driven by the internal electric field at the interfacial junction. In addition, 1% Bi2WO6-BiOCl exhibited excellent stability, and no apparent deactivation was observed after 4 test cycles. Therefore, the 0D/2D Bi2WO6-BiOCl heterojunction showed a great potential for the photocatalytic degradation of emerging organic pollutants.