Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing, 100083, PR China.
Dalton Trans. 2018 Dec 18;48(1):285-295. doi: 10.1039/c8dt03665a.
A carbon-coated molybdenum dioxide-reduced graphene oxide (RGO@MoO2/C) composite was synthesized as a high-performance electrode for supercapacitors via a facile hydrothermal method. In this composite, RGO not only provided high conductivity to benefit effective electron transfer, but also offered nucleation sites to load in situ formed MoO2/C nanoparticles. The MoO2@C nanoparticles interconnected with each other forming nanoclusters and were anchored uniformly on RGO sheets instead of self-agglomerating into large aggregates. This allowed more MoO2 grains to gain easy access to both the conductive network and the electrolyte for efficient electron and ion transfer. Moreover, this effect was achieved after the addition of a rather small amount of GO (5 wt%), which allowed high MoO2/C loading to contribute to the overall capacitance. When the RGO@MoO2/C composite was evaluated as an electrode material for supercapacitors, a synergistic effect was exerted with high specific capacitance (1224.5 F g-1 at 1 A g-1) and large reversibility (92% capacitance retention after 3000 cycles), both of which were of great advantage over individual MoO2/C composite. RGO@MoO2/C was also used to construct a symmetric supercapacitor, which showed enhanced voltage profiles and could light an LED device for dozens of minutes, thus confirming its excellent electrochemical performance.
一种碳包覆的二硫化钼还原氧化石墨烯（RGO@MoO2/C）复合材料，通过简便的水热法被合成出来，作为超级电容器的高性能电极。在这种复合材料中，RGO 不仅提供了高导电性，有利于有效电子转移，而且还提供了成核位点，以负载原位形成的 MoO2/C 纳米颗粒。MoO2@C 纳米颗粒相互连接形成纳米团簇，并均匀地锚定在 RGO 片上，而不是自聚集成大的聚集体。这使得更多的 MoO2 颗粒能够更容易地进入导电网络和电解质，从而实现有效的电子和离子转移。此外，在添加了少量 GO（5wt%）的情况下，就可以实现这种效果，从而允许高负载的 MoO2/C 有助于整体电容。当 RGO@MoO2/C 复合材料被评估为超级电容器的电极材料时，其表现出了协同效应，具有高比电容（1 A g-1 时为 1224.5 F g-1）和大的可逆性（3000 次循环后电容保持率为 92%），这两个特性都优于单独的 MoO2/C 复合材料。RGO@MoO2/C 还被用于构建对称超级电容器，其显示出增强的电压曲线，并可以点亮 LED 设备数十分钟，从而证实了其出色的电化学性能。
