Bhatt Aarti S, Ranjitha R, Santosh M S, Ravikumar C R, Prashantha S C, Maphanga Rapela R, Silva Guilherme F B Lenz E
Department of Chemistry, N.M.A.M. Institute of Technology (Visvesvaraya Technological University, Belagavi), Nitte 574110, India.
Department of Chemistry, St. Aloysius College (Autonomous), Mangaluru 575003, India.
Materials (Basel). 2020 Jul 2;13(13):2961. doi: 10.3390/ma13132961.
Nanostructured NiO and Li-ion doped NiO have been synthesized via a facile microwave technique and simulated using the first principle method. The effects of microwaves on the morphology of the nanostructures have been studied by Field Emission Spectroscopy. X-ray diffraction studies confirm the nanosize of the particles and favoured orientations along the (111), (200) and (220) planes revealing the cubic structure. The optical band gap decreases from 3.3 eV (pure NiO) to 3.17 eV (NiO doped with 1% Li). Further, computational simulations have been performed to understand the optical behaviour of the synthesized nanoparticles. The optical properties of the doped materials exhibit violet, blue and green emissions, as evaluated using photoluminescence (PL) spectroscopy. In the presence of Li-ions, NiO nanoparticles exhibit enhanced electrical capacities and better cyclability. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results show that with 1% Li as dopant, there is a marked improvement in the reversibility and the conductance value of NiO. The results are encouraging as the synthesized nanoparticles stand a better chance of being used as an active material for electrochromic, electro-optic and supercapacitor applications.
通过简便的微波技术合成了纳米结构的氧化镍和锂离子掺杂的氧化镍，并使用第一性原理方法进行了模拟。利用场发射光谱研究了微波对纳米结构形貌的影响。X射线衍射研究证实了颗粒的纳米尺寸以及沿（111）、（200）和（220）平面的择优取向，揭示了立方结构。光学带隙从3.3电子伏特（纯氧化镍）降至3.17电子伏特（掺杂1%锂的氧化镍）。此外，进行了计算模拟以了解合成纳米颗粒的光学行为。使用光致发光（PL）光谱评估，掺杂材料的光学性质表现出紫色、蓝色和绿色发射。在锂离子存在的情况下，氧化镍纳米颗粒表现出增强的电容和更好的循环性能。循环伏安法（CV）和电化学阻抗谱（EIS）结果表明，以1%锂作为掺杂剂时，氧化镍的可逆性和电导值有显著改善。这些结果令人鼓舞，因为合成的纳米颗粒有更好的机会用作电致变色、电光和超级电容器应用的活性材料。
