Horseradish Peroxidase-Coupled Ag 3 PO 4 /BiVO 4 Photoanode for Biophotoelectrocatalytic Degradation of Organic Contaminants.

Photoelectrocatalysis (PEC) is regarded as a promising and sustainable process for removal of organic contaminants from wastewater. Meanwhile, enzymatic catalysis also provides an effective way to carry out polluted environment remediation under mild conditions. In this study, a biophotoelectrocatalytic (BPEC) system is designed to remove 4-nitrophenol (4-NP) based on a combination of PEC and enzymatic catalysis. The developed BPEC system is constructed with a Ag 3 PO 4 /BiVO 4 photoanode and a horseradish peroxidase (HRP)-loaded carbon cloth (CC) cathode. On the photoanode, the construction of a direct Z-scheme Ag 3 PO 4 /BiVO 4 heterojunction enhanced the separation efficiency of photogenerated carriers, which promoted the PEC degradation of 4-NP under visible light irradiation. After HRP was immobilized on the cathode, the degradation efficiency of 4-NP reached 97.1 % after 60 min PEC treatment. The result could be ascribed to the HRP-catalyzed oxidation reaction via in situ-generated H 2 O 2 from the CC cathode during the PEC process. Moreover, the possible degradation pathways of 4-NP in such a BPEC system are also discussed.