A self-sufficient biocatalytic photo-Fenton system using immobilized glucose oxidase

Abstract

As one of the most popular advanced oxidation technologies, the Fenton reaction is widely used in industrial wastewater treatment. However, the conventional Fenton process requires continuous H₂O₂ addition and highly acidic conditions and thus is of high cost for practical applications and environmentally unfriendly. Herein, we report a self-sufficient biocatalytic Fenton process, in which H₂O₂ is generated in situ by a benign enzymatic reaction using glucose oxidase (GOD) and glucose. The hybrid catalyst is composed of Fe₃O₄ nanocrystals embedded in mesoporous graphitic carbon nitride nanosheets (Fe₃O₄/g-C₃N₄) that are loaded with the GOD enzyme. This new catalyst is robust and recyclable and works under neutral pH conditions. When tested on industrial coking wastewater, it efficiently lowers the chemical oxygen demand and readily converts refractory wastewater to be biotreatable. Compared to Fenton and Fenton-like systems already employed in industry, the hybrid catalyst will dramatically reduce chemical usage and environmental costs to enable a green and sustainable solution for wastewater treatment.