Bhardwaj Richa, Bharti Amardeep, Singh Jitendra P, Chae Keun Hwa, Goyal Navdeep, Gautam Sanjeev
Department of Physics, Panjab University, Chandigarh, 160014, India.
Advanced Analysis Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
Heliyon. 2018 Apr 9;4(4):e00594. doi: 10.1016/j.heliyon.2018.e00594. eCollection 2018 Apr.
An explicit study of comparison on the basis of structure and electronic properties of ZnO nanostructures was discussed. ZnO synthesized by sol-gel and hydrothermal method without using any surfactant leads to the formation of two different morphologies. Rietveld crystal structure refinement of X-ray diffraction patterns confirmed the wurtzite structure of both samples. Raman spectra also confirmed the wurtzite phase formation and improved crystallinity in sample synthesized by hydrothermal route that are concurrent with results obtained from X-ray diffraction. Field-emission scanning electron microscopy revealed the formation of ZnO spherical nanoparticle structure for sol-gel method and flower like structure for ZnO prepared through hydrothermal route. Williamson-Hall equations applied to study the strain and stress parameters present in the material, show the decrease in their values as the crystal size increases. Energy band gap is calculated using diffused reflectance spectroscopy. Near-edge X-ray absorption fine-structure measurements at O and Zn edges simulated with FEFF9.05 code confirmed the presence of oxygen vacancies. Further extended x-ray absorption fine-structure revealed a similar local atomic structure for both samples despite having different morphologies.
讨论了基于ZnO纳米结构的结构和电子性质进行的明确比较研究。通过溶胶-凝胶法和水热法合成的ZnO，在不使用任何表面活性剂的情况下会形成两种不同的形态。对X射线衍射图谱进行的Rietveld晶体结构精修证实了两个样品的纤锌矿结构。拉曼光谱也证实了水热法合成样品中纤锌矿相的形成以及结晶度的提高，这与X射线衍射得到的结果一致。场发射扫描电子显微镜揭示了溶胶-凝胶法制备的ZnO形成球形纳米颗粒结构，而水热法制备的ZnO形成花状结构。应用威廉姆森-霍尔方程研究材料中存在的应变和应力参数，结果表明随着晶体尺寸的增加，它们的值会降低。使用漫反射光谱法计算能带隙。用FEFF9.05代码模拟的O和Zn边缘的近边X射线吸收精细结构测量证实了氧空位的存在。进一步的扩展X射线吸收精细结构表明，尽管两种样品形态不同，但它们具有相似的局部原子结构。
