Abstract

In this work, Stipa capensis extract mediated the synthesis of Cu nanoparticles (Cu NPs) and their immobilization on the surface of nanostarch-coated Fe₃O₄. The prepared nanocatalyst (Cu NPs@Fe₃O₄-nanostarch) was characterized by fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS), field emission scanning electron microscopy (FESEM), thermogravimetric-differential thermal analysis (TG-DTA), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) analytical techniques. The nanocatalyst was used in selective oxidation of benzyl alcohol (BzOH) into benzaldehyde (BzH) by hydrogen peroxide under solvent-free reaction conditions. The synthesized magnetically recoverable nanocatalyst also showed high activity in the reduction of 4-nitrophenol (4-NP), 2,4-dinitrophenylhydrazine (2,4-DNPH), congo red (CR), methylene blue (MB), and potassium hexacyanoferrate(III) (K₃[Fe(CN)₆]) in water using NaBH₄ as the reduction agent at ambient temperature. Easy separation of catalyst, mild and eco-friendly reaction conditions, facile work-up, and the reusability of catalyst are some benefits of these methods.

摘要

在这项工作中，针茅提取物介导了铜纳米颗粒 (Cu NPs) 的合成及其在纳米淀粉包覆的 Fe ₃ O ₄表面上的固定化。制备的纳米催化剂（Cu NPs@Fe ₃ O ₄-nanostarch) 通过傅里叶变换红外光谱 (FTIR)、X 射线衍射 (XRD)、能量色散 X 射线光谱 (EDS)、场发射扫描电子显微镜 (FESEM)、热重-差热分析 (TG-DTA) 进行表征)、透射电子显微镜 (TEM) 和振动样品磁强计 (VSM) 分析技术。该纳米催化剂用于在无溶剂反应条件下通过过氧化氢将苯甲醇 (BzOH) 选择性氧化为苯甲醛 (BzH)。合成的磁性可回收纳米催化剂在还原 4-硝基苯酚 (4-NP)、2,4-二硝基苯肼 (2,4-DNPH)、刚果红 (CR)、亚甲蓝 (MB) 和六氰基高铁酸钾方面也显示出高活性(III) (K ₃ [Fe(CN) ₆ ]) 在水中使用 NaBH₄作为常温下的还原剂。催化剂易于分离、反应条件温和环保、易于处理以及催化剂的可重复使用性是这些方法的一些优点。