Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India.
Nanoscale. 2012 Oct 21;4(20):6604-12. doi: 10.1039/c2nr31831h.
The hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure photocatalyst has successfully been prepared by the reduction of nickel chloride hexahydrate using hydrazine hydrate through the solvothermal process at 140 °C followed by surface modification of the product by the reflux method at 110 °C for 1 h. The X-ray diffraction (XRD) pattern showed that the 'as prepared' sample consists of face centered cubic Ni and hexagonal wurtzite ZnO without any traces of impurity. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nickel nanoparticles under solvothermal conditions. These nickel nanoparticles, when subjected to reflux, formed the hexagonal zinc oxide coated nickel nanostructure. Fourier transform infrared (FTIR) spectra, photoluminescence (PL) and Raman studies also confirmed the presence of zinc oxide in the hybrid nanostructure. The growth mechanism for the development of the hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure has also been proposed. The appearance of the hysteresis loop, in the as-prepared Ni/ZnO hybrid nanostructure, demonstrated its ferromagnetic character at room temperature. The hexagonal Ni/ZnO nanostructure also acts as an efficient photocatalyst in the degradation of methylene blue under ultraviolet light irradiation. It is observed that the catalytic efficiency of the hybrid nanocatalyst is better compared to pure zinc oxide. Most importantly, the Ni/ZnO catalyst could also be easily separated, simply by applying an external magnetic field, and reused.
六角形氧化锌包覆镍（Ni/ZnO）纳米结构光催化剂通过在 140°C 下使用水合肼还原六水合氯化镍，然后通过回流法在 110°C 下对产物进行表面改性 1 小时，成功制备。X 射线衍射（XRD）图谱表明，“制备的”样品由面心立方 Ni 和六方纤锌矿 ZnO 组成，没有任何杂质痕迹。场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）图像证实了在溶剂热条件下形成了镍纳米颗粒。这些镍纳米颗粒在回流时形成了六角形氧化锌包覆镍纳米结构。傅里叶变换红外（FTIR）光谱、光致发光（PL）和拉曼研究也证实了杂化纳米结构中存在氧化锌。还提出了形成六角形氧化锌包覆镍（Ni/ZnO）纳米结构的生长机制。在制备的 Ni/ZnO 杂化纳米结构中出现滞后环表明其在室温下具有铁磁性。六角形 Ni/ZnO 纳米结构在紫外光照射下也能有效降解亚甲基蓝。观察到杂化纳米催化剂的催化效率优于纯氧化锌。最重要的是，Ni/ZnO 催化剂也可以通过施加外部磁场很容易地分离并重复使用。
