Abstract

Nickel hollow nanospheres (Ni HNSs) was prepared by solvothermal method using mixture of ethylenediamine (EN) and ethanol (ET), sodium borohydride as reducing agent and nickel chloride hexahydrate as precursor. The particle size of the Ni HNSs were tuned by varying several parameters including precursor concentrations, reaction temperatures (130–190 °C), and ET to EN volume ratios. The particle size and morphology of Ni HNSs were confirmed by dynamic light scattering and transmission electron microscope, respectively. Spherical shape of Ni nanoparticles of 300 nm size having ∼200 nm hollow space and 50 nm thickness was achieved at optimize condition of 4:6 volume ratio of ET/EN, 150 °C temperature, 0.1 M NaBH₄ concentration, and 7 h. Ni HNSs supported over SiO₂ (Ni HNSs/SiO₂) with different loading of Ni HNSs (1–10 wt.%) were prepared by impregnation method. The catalyst was characterized by X-ray diffraction, and inductively coupled plasma - optical emission spectroscopy. The catalytic performance of Ni HNSs/SiO₂ was carried out in the reduction of 4-Nitrophenol (4-NP) to 4 – Aminophenol (4-AP). 5 wt.% Ni HNSs/SiO₂ exhibited 87% reduction of 4-NP in 25 min and stable up to 6 catalyst cycles due to higher surface area of the catalyst.

摘要

以乙二胺（EN）和乙醇（ET）的混合物，硼氢化钠为还原剂，六水氯化镍为前驱体，采用溶剂热法制备镍空心纳米球（Ni HNSs）。通过改变几个参数来调整 Ni HNS 的粒径，包括前体浓度、反应温度 (130–190 °C) 和 ET 与 EN 的体积比。Ni HNSs的粒径和形貌分别通过动态光散射和透射电子显微镜确认。在 ET/EN 体积比 4:6、温度 150 ℃、浓度 0.1 M NaBH ₄和 7 h 的优化条件下，获得了尺寸为 300 nm、中空空间约为 200 nm、厚度为 50 nm 的 Ni 纳米颗粒的球形。SiO ₂上负载的Ni HNSs (Ni HNSs/SiO₂）通过浸渍法制备了不同负载量的Ni HNS（1-10 wt.%）。该催化剂通过X射线衍射和电感耦合等离子体-光学发射光谱进行表征。Ni HNSs/SiO ₂的催化性能是在将 4-硝基苯酚 (4-NP) 还原为 4-氨基苯酚 (4-AP) 的过程中进行的。5 wt.% Ni HNSs/SiO ₂在 25 分钟内表现出 87% 的 4-NP 还原率，并且由于催化剂的表面积更大而在多达 6 个催化剂循环中保持稳定。