Preparation of Z-Scheme BiVO4/g-C3N4/PANI Heterojunction and Its Photocatalytic Degradation of Enrofloxacin

Abstract

This study presents the synthesis and evaluation of a BiVO₄/g-C₃N₄/PANI ternary heterojunction photocatalyst for the degradation of enrofloxacin (ENR) under visible light irradiation. The results demonstrate that the BiVO₄/g-C₃N₄/PANI (10%) composite achieved a 91% removal efficiency of ENR within 120 min, following first-order kinetic behavior. Moreover, the photocatalyst exhibited stable degradation performance and maintained structural integrity after five consecutive cycles. The photocatalyst was characterized by XRD, SEM, TEM, FT-IR, XPS, and UV–vis DRS. The enhanced photocatalytic performance is attributed to the Z-scheme charge transfer mechanism facilitated by PANI, which enhances the separation of photogenerated carriers and reduces their recombination rate. Radical scavenging experiments and ESR spectroscopy confirmed that superoxide radicals (•O₂^–) and hydroxyl radicals (•OH) play dominant roles in the degradation process. Additionally, 15 degradation products of ENR were identified, and four major degradation pathways were proposed. The findings provide a theoretical basis for the application of this ternary heterojunction in environmental remediation and highlight its potential for efficient degradation of antibiotics.