In situ interfacial engineering of 1D Bi2S3/2D g-C3N4 heterostructures for antibiotics degradation in aqueous media via light mediated peroxymonosulfate activation

Abstract

Interfacial engineering between metal sulfides (MS) and graphitic carbon nitride (g-C₃N₄) offers a promising strategy to design semiconductors for the efficient degradation of persistent water pollutants. However, conventional multi-step methods used to prepare MS/g-C₃N₄ heterostructures often result in weak interfacial interactions between the building blocks, thereby leading to inefficient charge separation and sub-optimal catalytic performance. To overcome this limitation, we present here a novel single-step strategy for the in situ preparation of 1D Bi₂S₃(n)/2D g-C₃N₄ heterostructures, producing intimate interactions between the 1D and 2D architectures as evidenced by experimental and theoretical findings. Remarkably, these robust interfacial interactions establish a strong internal electric field (IEF), favoring spatial separation of high charge flux at the 1D/2D interface via an S-scheme mechanism. Importantly, the lowered charge transfer barrier at the interface speeds up the activation kinetics of peroxymonosulfate (PMS) and O₂, to achieve a high tetracycline degradation efficiency of 98.5% with a rate constant of 0.06 min⁻¹. DFT calculation results reveal that the effective coupling between the 1D/2D counterparts induced a charge redistribution and electron density accumulation at the interface, facilitating cleavage of the O–O bond in PMS and O₂. Furthermore, DFT calculations identified a unique PMS adsorption configuration on Bi sites and revealed the competence of S atoms in activating the peroxide bond in PMS. This work offers a cost-effective and environmentally friendly approach for the rational engineering of interfacial interactions in MS/g-C₃N₄ heterostructures, enabling highly efficient applications in energy and environmental remediation.