Department of Chemistry, State University of Maringa, Avenida Colombo 5790, CEP: 87020-900 Maringá, Paraná, Brazil.
Department of Physics, Federal University of Ceará, Av. das Universidades, 2853, CEP 60020-181 Fortaleza, CE, Brazil.
J Colloid Interface Sci. 2019 Nov 1;555:373-382. doi: 10.1016/j.jcis.2019.07.064. Epub 2019 Jul 25.
In recent years, electrochemical energy devices, i.e. batteries, fuel cells, solar cells, and supercapacitors, have attracted considerable attention of scientific community. The architecture of active materials plays a crucial role for improving supercapacitors performance. Herein, titanium dioxide (TiO) nanofibers (1D) have been synthesized by electrospinning process and used as a backbone to manganese dioxide (MnO) nanosheets (2D) growth through hydrothermal method. This strategy allows the obtaining of 1D/2D heterostructure architecture, which has demonstrated superior electrochemical performance in relation to pristine MnO. The highest electrochemical performance is due to the synergic effect between the metal oxides, where TiO nanofibers provide electrochemical stability for active MnO phase. Thus, the designed TiO@MnO structure can reach maximum specific capacitance of 525 F·g at a current density of 0.25 A·g, and it demonstrates an excellent stability by retaining 81% of the initial capacitance with coulombic efficiency of 91%. Therefore, the novel architecture of TiO@MnO based on nanofibers and nanosheets exhibits superior electrochemical properties to be used in supercapacitor applications.
近年来，电化学能量装置，如电池、燃料电池、太阳能电池和超级电容器，引起了科学界的极大关注。活性材料的结构对于提高超级电容器的性能起着至关重要的作用。在此，通过静电纺丝工艺合成了二氧化钛（TiO）纳米纤维（一维），并通过水热法将其用作二氧锰化（MnO）纳米片（二维）生长的骨架。这种策略允许获得一维/二维异质结构，与原始的 MnO 相比，其表现出卓越的电化学性能。最高的电化学性能归因于金属氧化物之间的协同效应，其中 TiO 纳米纤维为活性 MnO 相提供了电化学稳定性。因此，设计的 TiO@MnO 结构在电流密度为 0.25 A·g 时可达到 525 F·g 的最大比电容，并通过保持 81%的初始电容和 91%的库仑效率，表现出优异的稳定性。因此，基于纳米纤维和纳米片的 TiO@MnO 新型结构在超级电容器应用中表现出卓越的电化学性能。
