Novel biochar@CoFe2O4/Ag3PO4 photocatalysts for highly efficient degradation of bisphenol a under visible-light irradiation.

In the study, a series of novel Z-scheme biochar@CoFe2O4/Ag3PO4 photocatalysts were synthesized and employed to degrade bisphenol A under visible light irradiation (λ ≥ 420 nm). The structural morphology, optical properties and physicochemical properties of composites were characterized by means of TEM, XRD, FT-IR, XPS, UV-Vis, BET, EIS and VSM analysis. The photocatalytic performances of the photocatalysts were evaluated systematically. The MBA-3 photocatalyst exhibited the highest photocatalytic and mineralization ability within 60 min among all photocatalysts, 91.12% and 80.23%, respectively. After four cycles, the degradation of BPA still kept the photocatalytic activity of 73.94%, and the removal rate of TOC remained 58.96%. Moreover, the active species in the photocatalytic process were evaluated, and we proposed the Z-scheme photocatalytic mechanism for highly efficient degradation of BPA. According to the GC-MS results, the photodegradation pathway of BPA is also suggested. The present study has provided a valuable way of using the magnetic biochar in the design of new and efficient system for the degradation of organic pollutions in waste water.