Horseradish Peroxidase‐Coupled Ag₃PO₄/BiVO₄ Photoanode for Biophotoelectrocatalytic Degradation of Organic Contaminants

Abstract

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 Ag3PO4/BiVO4 photoanode and a horseradish peroxidase (HRP)‐loaded carbon cloth (CC) cathode. On the photoanode, the construction of a direct Z‐scheme Ag3PO4/BiVO4 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 H2O2 from the CC cathode during the PEC process. Moreover, the possible degradation pathways of 4‐NP in such a BPEC system are also discussed.

Cooperative Design of the Ag3PO4/NH2-MIL-88B (Fe/Co) Heterojunction Integrated with Conductive Polypyrrole for Advanced Photocatalytic Water Purification

“…There were noticeable differences in the Ag 3d spectrum from the photocatalytic fabrics (Figure b). In Ag@f, the Ag 3d 5/2 peak was deconvoluted into AgO at 366.1 eV and Ag 2 O at 367.3 eV, while the Ag 3d 3/2 peak was deconvoluted into AgO at 372.0 eV and Ag 2 O at 373.6 eV. − The deconvolution of the Ag 3d peak to AgO and Ag 2 O peaks appeared similarly for Ag/MIL@f and Ag/PPy/MIL@f. Also, the peak ratio of Ag 2 O/AgO in Ag/MIL@f and Ag/PPy/MIL@f increased compared to that of Ag@f. Such changes in the binding energy and peak ratio evince the chemical interactions between Ag 3 PO 4 and MIL as a result of the successful construction of the heterojunction . For Ag/PPy/MIL@f, new peaks for the reduced form of Ag metal (Ag 0 ) appeared at 372.4 and 374.4 eV, which may result from the enhanced charge transfer ability by the heterojunction .…”

“…In comparison to MIL@f, Ag/MIL@f displayed a higher intensity of C–N peak (399.8 eV), due to the electron density change attributable to interactions between MIL and Ag 3 PO 4 . 50 , 54 The Ag/PPy/MIL@f showed a higher intensity for C–N than for – NH 2 ( Figure S7 ), due to the presence of pyrrolic C–N in PPy. 58 Ag/PPy/MIL@f showed a new peak at 401.4 eV corresponding to the Fe–N pyrrole bond due to the successful PPy synthesis on the MIL surface.…”