Highly active heterogeneous Fe-based catalysts synergistically enhanced by polyaniline and MoS2 for organic contaminant elimination†

Fe-based catalysts have garnered significant attention due to their high stability, low toxicity and cost-effectiveness, while the construction of highly active heterogeneous Fe-based catalysts through a simple method is still challenging in the environmental catalysis field. Herein, employing the synergistic enhancement effect of the conductive polymer polyaniline (PANI) and co-catalyst MoS₂, a highly active PANI-supported Fe-doped MoS₂ catalyst (PANI-Fe@MoS₂) was prepared via a facile one-step hydrothermal process. Surprisingly, PANI incorporation induced critical structural modifications, including reduced average particle size (1 μm), expanded interlayer spacing (1.09 nm), and enhanced sulfur vacancy density. Interestingly, PANI-Fe@MoS₂ achieved nearly 100% elimination of carbamazepine (CBZ) within 10 min, and its removal efficiency (k-value) surpassed most of those reported in the literature. Notably, PANI-Fe@MoS₂ exhibited a high removal of TOC (nearly 50%), a wide pH operating range (2–10), and outstanding removal efficiency for various contaminants. Additionally, the quenching and electron paramagnetic resonance (EPR) experiments revealed that singlet oxygen (¹O₂) and hydroxyl radicals (˙OH) were the main reactive oxygen species (ROSs) for degrading CBZ. Moreover, the potential degradation pathways were proposed based on the intermediates of CBZ. This work provides a strategic paradigm for designing efficient heterogeneous Fe-based catalysts for environmental remediation.