Facile synthesis of a direct Z -scheme BiOCl-phosphotungstic acid heterojunction for the improved photodegradation of tetracycline.

The fabrication of a Z -scheme heterojunction photocatalyst can effectively modulate the electron transfer and separation of photoinduced charge carriers to enhance photocatalytic performance. Here, we demonstrate a direct Z -scheme BiOCl-phosphotungstic acid (BiOCl-HPW) heterojunction, fabricated via a one-step hydrothermal synthesis, as a highly active and stable photocatalyst for the photodegradation of tetracycline. BiOCl-HPWs result in a dramatic improvement in visible-light utilization and photogenerated e - and h + separation, as well as a decrease in the electrical resistance by the addition of HPW. Notably, the BiOCl-HPW heterojunction with optimized phosphotungstic acid (HPW) content achieved an outstanding photodegradation rate of tetracycline (0.0195 min -1 ). A reasonable Z -scheme photocatalytic mechanism based on the analysis of band structure and monitoring of active radicals is proposed. This study highlights the potential implications of the BiOCl-HPW heterojunctions in the photodegradation of other toxic chemicals and photocatalytic studies.