A novel photo-enzyme coupling catalysis system with electronic channels for the degradation of bisphenol a in water

Abstract

How to enhance the efficiency of electron transfer between the photocatalytic system and the enzymatic catalytic system is the key to constructing novel and efficient photo-enzyme coupling system. Hence, polypyrrole (Ppy) with high adsorbability was employed as a bridge to establish an electron transfer pathway between the photocatalytic system and the enzymatic catalytic system in this work, enhancing both the immobilized amount of the biocatalyst and the efficiency of electron transfer and catalytic activity in the photo-enzyme coupling system. After immobilization optimization, the unit loading of horseradish peroxidase (HRP) can reach 831.00 mg/g, and the immobilized HRP has strong pH stability, storage stability and cycling stability. Moreover, the conversion efficiency (Kcat/Km) of immobilized HRP was 0.4800 min−1 mM−1, higher than that of free HRP (0.1560 min−1 mM−1). Moreover, the successful construction of the photo-enzyme coupling system was confirmed by a series of physical characterization, such as FT-IR, XRD, TGA and XPS. In the degradation experiment of bisphenol A (BPA), the degradation rate of BPA by HRP/Ppy/CN photo-enzyme coupling system can reach 86.03 % within 60 min and rate constant is 0.0329 min−1, which is 1.91 times and 3.19 times that of pure g-C3N4, respectively. This work provides a new idea for the development of an efficient photo-enzyme coupled catalytic system and the effective removal of phenols in water.