A twin S-scheme CoFe2O4/VCNDA/BiVO4 nanozyme for photo-auto-enzyme-coupled catalytic degradation of carbamazepine

Abstract

The photo-enzyme-coupled catalytic (PECC) system combines the high selectivity of enzymatic reaction with the unique activity of photocatalytic reaction, which shows great application potential in the field of organic pollutant degradation. However, the traditional PECC system usually requires additional to enzyme substrates to achieve the enzymatic reaction, which increases the risk of environmental pollution. Herein, the twin S-scheme CoFe2O4/vesicular g-C3N4-FeCoDA/BiVO4 (CVBDA) nanozyme with good horseradish peroxidase (HRP) activity was prepared and used to construct the unique photo-auto-enzyme-coupled catalytic (PAECC) system. The twin S-scheme mechanism was confirmed by the XPS and UPS. In this heterojunction, the strong redox ability of CVBDA nanozyme can be effectively retained for the efficient degradation of pollutants and catalysis of oxygen reduction reactions. And the abundant H2O2 provided by the oxygen reduction reaction lays the foundation for excellent HRP activity and effectively increases the amount of active group to improve the oxidation performance of CVBDA nanozyme. With 1 mg/L carbamazepine as the target contaminant, the degradation efficiency of CVBDA nanozyme can reach 90.9 % in the PAECC system. This study provides a new idea for the design of twin S-scheme nanozyme to improve the catalytic performance of photo-enzyme-coupled catalytic system.