Construction of a Well-Defined S-Scheme Heterojunction Based on Bi-ZnFe 2 O 4 /S-g-C 3 N 4 Nanocomposite Photocatalyst to Support Photocatalytic Pollutant Degradation Driven by Sunlight.

Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe₂O₄) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe₂O₄/S-g-C₃N₄) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe₂O₄ was verified, and the 9%Bi-ZnFe₂O₄ nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe₂O₄ NPs were homogenized with varying amounts of S-g-C₃N₄ (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe₂O₄/30%S-g-C₃N₄ (BZFG-30) composite outperformed ZnFe₂O₄, S-g-C₃N₄ and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe₂O₄/S-g-C₃N₄ interconnection. The proposed modification of ZnFe₂O₄ using Bi and S-g-C₃N₄ is effective, inexpensive, and environmentally safe. [ABSTRACT FROM AUTHOR]