Magnetic and hydroxylated carbon nanotubes (NiCNTs-OH) were synthesized in situ via a green, facile, and efficient water-assisted chemical vapor deposition (H₂O-CVD) method. Pd nanoparticles (NPs) were then anchored to the surfaces of the NiCNTs-OH and the resulting Pd/NiCNTs-OH were studied for their catalytic efficiency in the Heck reaction. Transmission electron microscopy images show that the prepared Pd/NiCNTs-OH consist of a CNT-based framework with Pd NPs of 2–4 nm and Ni NPs encapsulated by the tubes. Vibrating sample magnetometer measurements reveal that the catalysts are easily recycled by magnetic separation. Raman spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations suggest that defects and oxygen-containing groups are introduced by the H₂O-CVD method, providing sufficient anchoring sites for Pd NP loading. Hence, the Pd/NiCNTs-OH exhibit excellent yields in the Heck reaction of various aryl iodides with methyl acrylate. This work thus demonstrates a green and facile method for the preparation of magnetic nano-catalysts that can be employed for various catalytic reactions.

磁性和羟基化的碳纳米管（NiCNTs-OH）通过绿色，简便且有效的水辅助化学气相沉积（H ₂ O-CVD）方法原位合成。然后将Pd纳米颗粒（NPs）固定在NiCNTs-OH的表面，并研究了所得Pd / NiCNTs-OH在Heck反应中的催化效率。透射电子显微镜图像显示，所制备的Pd / NiCNTs-OH由具有2-4 nm的Pd NP和被管封装的Ni NP的基于CNT的骨架组成。振动样品磁力计的测量表明，催化剂易于通过磁分离回收。拉曼光谱，X射线光电子能谱和密度泛函理论计算表明，H ₂引入了缺陷和含氧基团O-CVD方法，为Pd NP负载提供足够的锚固位点。因此，Pd / NiCNTs-OH在各种芳基碘化物与丙烯酸甲酯的Heck反应中显示出极好的收率。因此，这项工作证明了一种绿色简便的制备磁性纳米催化剂的方法，该方法可用于各种催化反应。