Novel Z-scheme Ag3PO4/Fe3O4-activated biochar photocatalyst with enhanced visible-light catalytic performance toward degradation of bisphenol A

Abstract

A novel solid-state Z-scheme heterostructure, Ag3PO4/Fe3O4 co-doped bamboo-derived activated biochar (Ag–Fe@BAB), was synthesized as an efficient photocatalyst via a co-precipitation method. Ag–Fe@BAB was used as a magnetically recoverable photocatalyst to generate free radical species with peroxydisulfate (PDS) activation under visible-LED-light illumination. The successful synthesis of Ag–Fe@BAB was confirmed by various characterization techniques. Bisphenol A (BPA) was used as a model pollutant to evaluate the photocatalytic activities of the Vis/Ag–Fe@BAB/PDS system. To confirm the photocatalytic performance of the Vis/Ag–Fe@BAB/PDS system, the effects of significant operating parameters such as the contact time, concentration of oxidant, photocatalyst dosage, and solution pH on the degradation of BPA were evaluated. We confirmed that 95.6% BPA was degraded within 60 min in the Vis/Ag–Fe@BAB/PDS system under 1.0 g/L photocatalyst, pH 6.5, and 0.5 mM PDS. The degradation mechanism of BPA in the Vis/Ag–Fe@BAB/PDS system was mainly attributed to O2‾ owing to its photocatalytic performances in the presence of p-benzoquinone as a scavenger. Furthermore, the radical species produced in the Vis/Ag–Fe@BAB/PDS system were identified by electron spin resonance. Finally, we demonstrated the recyclability of the Ag–Fe@BAB photocatalyst through its excellent magnetic property.