SiO2 Stabilized Magnetic Nanoparticles as a Highly Effective Catalyst for the Degradation of Basic Fuchsin in Industrial Dye Wastewaters

Abstract

Catalytic degradation of organic pollutants by nanomaterials is an effective way for environmental remediation. The Fenton reaction involving H₂O₂ oxidation catalysed by Fe³⁺ is an advisable way for wastewater degradation. Herein, Fe₃O₄/SiO₂ core-shell nanoparticles were prepared as catalyst by coprecipitation and sol-gel methods, and this catalyst is used for degradation of fuchsin in wastewater by H₂O₂. The Fenton reaction between H₂O₂ and Fe₃O₄ is proposed to explain the catalytic performance. The coating of SiO₂ on Fe₃O₄ nanoparticles could dramatically stabilize the Fe₃O₄ in aqueous solution and prevent their oxidation. More importantly, the magnetic property of Fe₃O₄ nanoparticles endows them with good recyclability. Thus, due to the outstanding catalytic results, almost 100% removal degradation was achieved within 5 min over a wide pH value range at room temperature, which is better than that without catalysts. Temperature is a positive factor for improving the degradation rate, but room temperature is selected as the best temperature for economic and energy savings reasons, because more than 98% of fuchsins can still be degraded at room temperature. Moreover, these Fe₃O₄/SiO₂ core-shell nanoparticles exhibit excellent magnetic recyclability and stable properties after repeated utilization. Therefore, these as-presented Fe₃O₄/SiO₂ core-shell nanoparticles with low-cost and high performance are expected to be applied in practical industry wastewater degradation.