Construction of dual Z-scheme BiWO/g-CN/black phosphorus quantum dots composites for effective bisphenol A degradation.

In this work, a novel dual Z-scheme BiWO/g-CN/black phosphorus quantum dots (BiWO/g-CN/BPQDs) composites were fabricated and utilized towards photocatalytic degradation of bisphenol A (BPA) under visible-light irradiation. Optimizing the content of g-CN and BPQDs in BiWO/g-CN/BPQDs composites to a suitable mass ratio can enhance the visible-light harvesting capacity and increase the charge separation efficiency and the transfer rate of excited-state electrons and holes, resulting in much higher photocatalytic activity for BPA degradation (95.6%, at 20 mg/L in 120 min) than that of BiWO (63.7%), g-CN (25.0%), BPQDs (8.5%), and BiWO/g-CN (79.6%), respectively. Radical trapping experiments indicated that photogenerated holes (h) and superoxide radicals (•O) played crucial roles in photocatalytic BPA degradation. Further, the possible degradation pathway and photocatalytic mechanism was proposed by analyzing the BPA intermediates. This work also demonstrated that the BiWO/g-CN/BPQDs as effective photocatalysts was stable and have promising potential to remove environmental contaminants from real water samples.