A synergistic 2D/2D g-C3N4/BiOI heterojunction-driven photocatalytic self-Fenton system for efficient mineralization of refractory organic pollutants

Abstract

Photocatalysis self-Fenton (PSF) represents a promising approach for organic pollutant treatment, yet existing photocatalysts suffer from insufficient degradation efficiency and mineralization. Here, we construct a 2D/2D interfacial heterojunction system through the integration of g-C₃N₄ and BiOI nanosheets, targeting efficient decomposition and thorough mineralization of persistent organic pollutants. Under visible-light irradiation, this system efficiently generates H₂O₂ via an oxygen reduction pathway, and subsequently activates a Fenton reaction, producing highly reactive ·OH radicals. Complete degradation of bisphenol A was achieved within 60 min, accompanied by a mineralization rate of 64.4%. The system also demonstrates superior performance across various pollutants, exhibiting excellent versatility. Experimental characterization and theoretical calculation reveal that the type-I band alignment at the heterointerface drives photogenerated carrier separation through a built-in electric field, while the 2D architecture enhances charge transfer efficiency. This study provides both theoretical and technical insights into the design and application of PSF systems in environmental remediation.