Enhanced activation of PMS by a novel Fenton-like composite Fe ₃O ₄/S-WO ₃ for rapid chloroxylenol degradation

Graphical abstract

Abstract

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 Fe ₃O ₄ nanoparticles with S-WO ₃ (X-Fe ₃O ₄/S-WO ₃) to accelerate the Fe ²⁺/Fe ³⁺ cycle. The composite has outstanding PCMX degradation and peroxymonosulfate (PMS) decomposition efficiency over a wide pH range (3.0 ∼ 9.0). 80-Fe ₃O ₄/S-WO ₃/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 Fe ₃O ₄ 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 ^•, SO ₄ ^•− and ¹O ₂. The degradation pathways of PCMX were analyzed in detail. The component WS ₂ in S-WO ₃ plays a co-catalytic role instead of WO ₃. And the exposed active W ⁴⁺ _surf. efficiently enhanced the Fe ³⁺/Fe ²⁺ cycle, thereby complete PMS decomposition and high catalytic efficiency were achieved. Our findings clarify that applying two-dimensional transition metal sulfide WS ₂ to modify heterogeneous Fe ₃O ₄ is a feasible strategy to improve Fenton-like reaction and provide a promising catalyst for PCMX degradation.