Enhanced activation of PMS by a novel Fenton-like composite Fe3O4/S-WO3 for rapid chloroxylenol degradation

Chloroxylenol (PCMX) is widely used as disinfectant since the epidemic outbreak due to its effective killing of Covid-19 virus. Its stable chemical properties make it frequently detected in surface water. Herein, we successfully modified Fe3O4 nanoparticles with S-WO3 (X-Fe3O4/S-WO3) to accelerate the Fe2+/Fe3+ cycle. The composite has outstanding PCMX degradation and peroxymonosulfate (PMS) decomposition efficiency over a wide pH range (3.0 similar to 9.0). 80-Fe3O4/S-WO3/PMS system not only increased PMS decomposition efficiency from 27.7% to 100.0%, but also realized an enhancement of PCMX degradation efficiency by 16 times in comparison with that of Fe3O4 alone. The catalyst utilization efficiency reached 0.3506 mmol.g(-1).min(-1) which stands out among most Fenton-like catalysts. The composite has excellent degradation ability to a variety of emerging pollutants, such as antibiotics, drugs, phenols and endocrine disrupters, and at least a 90% removal efficiency reached in 10 min. The degradation of PCMX was dominated by HO center dot, SO4 center dot- and O-1(2). The degradation pathways of PCMX were analyzed in detail. The component WS2 in S-WO3 plays a co-catalytic role instead of WO3. And the exposed active W-surf(4+). efficiently enhanced the Fe3+/Fe2+ cycle, thereby complete PMS decomposition and high catalytic efficiency were achieved. Our findings clarify that applying two-dimensional transition metal sulfide WS2 to modify heterogeneous Fe3O4 is a feasible strategy to improve Fenton-like reaction and provide a promising catalyst for PCMX degradation.