This study focuses on preparation of a novel Fe 3 O 4 @C/RM composite by carbothermal reduction of red mud (RM) with scrap tire-derived carbon black and its application for the degradation of orange II in water by activating PMS. X-ray diffraction (XRD) measurements revealed that hematite (Fe 2 O 3 ) was reduced to Fe 3 O 4 in the pyrolysis process above 600 o C. The reduction pathway of Fe 2 O 3 was inferred by detecting the gas emissions during carbothermal reduction. Morphology analysis indicates that Fe 3 O 4 nanoparticles were encapsulated in a carbon matrix, forming a composite with the residual components of RM. The as-prepared Fe 3 O 4 @C/RM composite exhibited high performance toward orange II degradation with 95.9% removal of orange II within 90 min. Electron paramagnetic resonance (EPR) and quenching tests were applied to illustrate the activation processes of peroxymonosulfate. Both radical and non-radical oxygen species are responsible for the efficient degradation of orange II in the Fe 3 O 4 @C/RM/PMS system.
Wei Sun,Qing Xu,Qili Liu,Tianliang Wang,Zhaixin Liu
Efficient magnetic solid phase extraction using covalent organic frameworks (COFs) can find important applications in food safety. In this work, a sulfonate-functionalized magnetic COF (Fe 3 O 4 @COF-SO 3 Na) was synthesized by self-polycondensation of two-in-one monomer 1,6-bis(4-formylphenyl)-3,8-bis((4-aminophenyl) ethynyl)) pyrene (BFBAEPy) on the surface of aminated Fe 3 O 4 and a thiol-yne click reaction. It was further adopted as an adsorbent for the efficient magnetic solid-phase extraction (MSPE) of basic orange II. The selective adsorption experiment indicated that it displayed selective adsorption ability to basic orange II due to the ion exchange, hydrogen bonds, and π-π interactions. Under the optimized conditions, the proposed MSPE method coupled with HPLC-DAD showed excellent linearity in the range of 0.05–0.5 µg/mL (R 2 = 0.9997) for basic orange II. The lower limits of detection (LODs) for basic orange II were 1.0–1.4 µg/L for three food samples: yellow croaker, paprika and dried bean curd. The recoveries were 90.1–98.8% with relative standard deviations (RSDs) below 4.2%. Therefore, this work provides an effective strategy to modify magnetic COFs as absorbents in MSPE. Due to the tunability of functional groups in thiol‑yne click reactions, the functional groups of magnetic COFs can be readily designed to enrich their multifunctional applications. Meanwhile, this work proposed a new method to detect trace amounts of basic orange II in food samples.
危险品化学品经营许可证（带存储）