Anand G Theophil, Kennedy L John
Materials Division, School of Advanced Sciences, Vellore Institute of Technology (VIT) University, Chennai Campus, Chennai 600127, Tamil Nadu, India.
J Nanosci Nanotechnol. 2013 Apr;13(4):3096-103. doi: 10.1166/jnn.2013.7428.
Porous Zn(1-x)Cu(x)Al2O4 (x = 0, 0.1,0.2, 0.3, 0.4, 0.5) spinel nanostructures were synthesized by one-pot microwave combustion technique. All the samples were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and scanning electron microscopy (SEM). The XRD patterns confirm the formation of single phase ZnAl2O4 without any impurities. The results of XRD indicated the average crystallite size in the range of 12.44-22.86 nm. FT-IR spectra show the vibrational stretching frequencies corresponding to the zinc aluminate spinel structure. The estimated band gap of undoped ZnAl2O4 was 4.96 eV indicating the quantum confinement phenomenon. DRS spectra also indicated the band gap narrowing effect with increase in copper ion concentrations. The defect centers acting as trap levels were obtained from photoluminescence studies responsible for the emission spectra. SEM images showed the features of well created pore structures in all the matrices. The percentage porosity of zinc aluminate matrices decreased with increasing copper doping.
采用一锅法微波燃烧技术合成了多孔Zn(1-x)Cu(x)Al2O4（x = 0、0.1、0.2、0.3、0.4、0.5）尖晶石纳米结构。使用X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、漫反射光谱（DRS）、光致发光（PL）和扫描电子显微镜（SEM）对所有样品进行了表征。XRD图谱证实形成了无任何杂质的单相ZnAl2O4。XRD结果表明平均晶粒尺寸在12.44 - 22.86 nm范围内。FT-IR光谱显示了与锌铝酸盐尖晶石结构相对应的振动拉伸频率。未掺杂的ZnAl2O4的估计带隙为4.96 eV，表明存在量子限制现象。DRS光谱也表明随着铜离子浓度的增加带隙变窄效应。从负责发射光谱的光致发光研究中获得了作为陷阱能级的缺陷中心。SEM图像显示了所有基体中良好形成的孔结构特征。随着铜掺杂量的增加，锌铝酸盐基体的孔隙率百分比降低。
