Magnetic core–shell nanomaterial Fe₃O₄–SiO₂–Cu₂O/Cu was first successfully synthesized using an economical strategy. Using Fe₃O₄ as a magnetic center for easy recycling and SiO₂ as the connecting layer, Cu elements were evenly and steadily distributed on the surface of the Fe₃O₄–SiO₂–Cu₂O/Cu core–shell nanostructure. The magnetic catalyst performed outstanding catalytic reduction activity for 4-nitrophenol (4-NP), and the complete catalytic reduction of 4-NP was achieved within only 5 min. What’s more, the catalyst could be well recycled, and the catalytic efficiency remained more than 90% after being reused 24 times.

Graphical abstract

中文翻译：

---

可回收磁性Fe3O4–SiO2–Cu2O/Cu核壳纳米催化剂的制备，高效还原芳香族硝基化合物

磁性核壳纳米材料 Fe ₃ O ₄ –SiO ₂ –Cu ₂ O/Cu 是首次使用经济策略成功合成。以Fe ₃ O ₄为易于回收的磁性中心和SiO _{2作为连接层，Cu元素均匀稳定地分布在Fe 3} O ₄ –SiO ₂ –Cu ₂表面O/Cu 核壳纳米结构。该磁性催化剂对 4-硝基苯酚 (4-NP) 具有出色的催化还原活性，仅需 5 分钟即可实现 4-NP 的完全催化还原。此外，该催化剂具有良好的循环利用性，重复使用24次后，催化效率仍保持在90%以上。

图形概要