ZIF-8 assisted synthesis of magnetic core-shell Fe 3 O 4 @CuS nanoparticles for efficient sulfadiazine degradation via H 2 O 2 activation: Performance and mechanism.

A novel magnetic core-shell Fe ₃ O ₄ @CuS have been successfully synthesized by chemical etching and cation exchange method using Zeolitic imidazolate frameworks (ZIF) as the template. The morphology and microstructural properties characterization indicated that Fe ₃ O ₄ @CuS nanoparticles were rhombic dodecahedral shape, highly stable, and magnetic with a large specific surface area (772.20 m ² /g). The catalytic activity of Fe ₃ O ₄ @CuS was assessed on sulfadiazine (SDZ) degradation by H ₂ O ₂ activation. Multi-factors affecting the SDZ removal was adequately investigated. Approximately 93.2% SDZ (50 μM) was removed with 0.2 g/L Fe ₃ O ₄ @CuS and 5 mM H ₂ O ₂ in 90 min. In particular, Fe ₃ O ₄ @CuS exhibited a quality catalytic performance within a wide pH range of 3.0-11.0. Radical scavenger tests and electron paramagnetic resonance (EPR) analysis confirmed that •O ₂ ^- , •OH, and ¹ O ₂ all contributed to the SDZ degradation, and •OH played the dominant role. Meanwhile, mechanism investigation suggested that the effective catalytic activity of Fe ₃ O ₄ @CuS could be ascribed to the sulphur-enhanced copper-based Fenton reaction on the CuS shell, sulphur-enhanced iron-based Fenton reaction on the Fe ₃ O ₄ core, and the effective electron transfer between the shell and core. Finally, the possible SDZ degradation pathways were further proposed on the basis of the intermediates identification. This work put forward a new strategy to synthesize magnetic core-shell Fe ₃ O ₄ @CuS using ZIF-8 as the template with outstanding performance for H ₂ O ₂ activation to degrade SDZ.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021 Elsevier Inc. All rights reserved.)