Graphene-directed Z-scheme charge transfer in a bismuth ferrite-based ternary heterojunction for efficient...

While advanced oxidation processes (AOPs) play a crucial role in degrading persistent antibiotics, conventional approaches are fundamentally constrained by severe carrier recombination and harsh pH requirements, highlighting the need for new synergistic catalytic systems. Heterojunction catalysts offer a promising route to mitigate these drawbacks by promoting directional charge transfer; however, in multicomponent systems, precisely controlling charge migration pathways remains a key bottleneck. In this study, we proposed a novel charge-regulation strategy by introducing graphene oxide (GO) as an "electron relay station" into a newly constructed La-BiFeO₃@Fe₃O₄-GO ternary heterojunction, enabling the directional transport of photogenerated carriers along a highly efficient Z-scheme pathway. Benefiting from this design, the catalyst retained strong redox potentials on both semiconductors, achieving 95.5 % degradation of ofloxacin within 60 min, alongside excellent recyclability and stability with negligible metal leaching under near-neutral pH conditions. This outstanding performance, jointly verified by photoelectrochemical measurements, radical trapping, first-principles calculations, and experimental band alignment, originated from efficiently separating charge carriers and the generation of abundant ·OH and ·O₂^- active species through the Z-scheme mechanism. This work establishes a generalizable approach for rationally controlling charge transfer pathways in multicomponent heterojunctions via conductive interfaces, offering a scalable route to the advancement of high-efficiency environmental catalysts for antibiotic remediation.