Sharifi Samira, Rahimi Kourosh, Yazdani Ahmad
Condensed Matter Physics Group, Department of Basic Sciences, Tarbiat Modares University, Jalal-Ale-Ahmad Avenue, Tehran, Iran.
Sci Rep. 2021 Apr 16;11(1):8378. doi: 10.1038/s41598-021-87823-6.
Manganese ferrite (MnFeO) nanoparticles were synthesized via a hydrothermal method and combined with exfoliated MoS nanosheets, and the nanocomposite was studied as a supercapacitor. X-ray diffractometry and Raman spectroscopy confirmed the crystalline structures and structural characteristics of the nanocomposite. Transmission electron microscopy images showed the uniform size distribution of MnFeO nanoparticles (~ 13 nm) on few-layer MoS nanosheets. UV-visible absorption photospectrometry indicated a decrease in the bandgap of MnFeO by MoS, resulting in a higher conductivity that is suitable for capacitance. Electrochemical tests showed that the incorporation of MoS nanosheets largely increased the specific capacitance of MnFeO from 600 to 2093 F/g (with the corresponding energy density and power density of 46.51 Wh/kg and 213.64 W/kg, respectively) at 1 A/g, and led to better charge-discharge cycling stability. We also demonstrated a real-world application of the MnFeO/MoS nanocomposite in a two-cell asymmetric supercapacitor setup. A density functional theory study was also performed on the MnFeO/MoS interface to analyze how a MoS monolayer can enhance the electronic properties of MnFeO towards a higher specific capacitance.
通过水热法合成了锰铁氧体（MnFeO）纳米颗粒，并将其与剥离的MoS纳米片相结合，对该纳米复合材料作为超级电容器进行了研究。X射线衍射和拉曼光谱证实了纳米复合材料的晶体结构和结构特征。透射电子显微镜图像显示了MnFeO纳米颗粒（约13纳米）在少层MoS纳米片上的均匀尺寸分布。紫外可见吸收光谱表明，MoS使MnFeO的带隙减小，从而导致更高的电导率，适合于电容。电化学测试表明，在1 A/g的电流密度下，加入MoS纳米片使MnFeO的比电容从600大幅提高到2093 F/g（相应的能量密度和功率密度分别为46.51 Wh/kg和213.64 W/kg），并带来了更好的充放电循环稳定性。我们还展示了MnFeO/MoS纳米复合材料在双电池不对称超级电容器装置中的实际应用。还对MnFeO/MoS界面进行了密度泛函理论研究，以分析MoS单层如何增强MnFeO的电子性能以实现更高的比电容。
