期刊
NEW JOURNAL OF CHEMISTRY
卷 46, 期 4, 页码 1665-1676出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/d1nj05085k
关键词
-
资金
- National Natural Science Foundation of Hebei Province [E2019402213]
- Programs Foundation of Hebei University of Engineering [SJ2101003016, SJ2101003025]
Porous nanopetals of MnMoO4 with oxygen vacancies exhibit higher specific surface area and more diverse pore size distribution compared to MnMoO4 nanopetals. The introduction of oxygen vacancies leads to decreased energy band gap, increased electron state distribution at Fermi energy level, enhanced specific capacitance, and improved capacitance retention rate for MnMoO4-OV. These results demonstrate the beneficial effects of oxygen vacancies on the supercapacitive performance of MnMoO4-OV.
Porous nanopetals of MnMoO4 with oxygen vacancies were prepared by hydrothermal synthesis and a hydrogenation reduction method. MnMoO4-OV porous nanopetals have a higher specific surface area together with a more diverse pore size distribution than MnMoO4 nanopetals. The density functional theory calculation results reveal that MnMoO4-OV has a lower energy band gap (0.642 eV) than MnMoO4 (1.095 eV). The electronic density of states plots reveal that MnMoO4-OV displays more electron state distribution at the Fermi energy level than MnMoO4. The MnMoO4-OV porous nanopetals achieve a higher specific capacitance (1920 g(-1)) than MnMoO4 (921 F g(-1)) at 1 A g(-1). They also achieve a superior capacitance retention rate (85.5%) to that of MnMoO4 (69.1%) with the current density increasing from 1 to 10 A g(-1). The introduction of oxygen vacancies can increase the carrier density, accelerate the electron transfer, enhance the electrical conductivity, and accordingly strengthen the redox reactivity of MnMoO4-OV. An asymmetric supercapacitor was also constructed by using MnMoO4-OV as the positive electrode and activated carbon as the negative electrode. It achieves a high energy density of 59.8 W h kg(-1) at a power density of 750 W kg(-1), together with a good cycle life. Both experimental measurements and theoretical calculations were conducted to prove the promotive role of oxygen vacancies in achieving the supercapacitive performance of MnMoO4-OV.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据