Facile low-temperature synthesis of hematite quantum dots anchored on a three-dimensional ultra-porous graphene-like framework as advanced anode materials for asymmetric supercapacitors
Facile low-temperature synthesis of hematite quantum dots anchored on a three-dimensional ultra-porous graphene-like framework as advanced anode materials for asymmetric supercapacitors
复制标题
轻松低温合成锚定在三维超多孔类石墨烯框架上的赤铁矿量子点，作为不对称超级电容器的先进阳极材料
DOI：
10.1039/c6ta02927b
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发表时间：
2016-01-01
影响因子：
11.9
通讯作者：
Guo, Zaiping
中科院分区：
文献类型：
--
作者：
Li, Yunyong;Zhang, Haiyan;Guo, Zaiping
通过简单且可扩展的策略设计了一种复合材料，该复合材料由锚定在三维超多孔石墨烯类框架（表示为 Fe2O3-QDs-3D GF）上的分散良好的超细赤铁矿量子点（类似于 2.7 nm）组成。在该复合材料中，具有高电导率和高表面积的超多孔3D GF被用作具有表面缺陷位点的导电基体，用于均匀分散的超小Fe2O3-QD的可控生长。石墨烯框架可以紧紧地容纳大量的Fe2O3-QDs，从而确保活性材料的高利用率和单个Fe2O3-QDs所需的导电性。锚定在3D GF上的超小尺寸Fe2O3-QD可以赋予复合材料优异的高表面积和足够的电化学反应活性位点，从而赋予复合材料较大的比电容。正如预期的那样，所制备的 Fe2O3-QDs-3D GF 电极在 2.0 mol L-1 KOH 水溶液中的三电极体系中在 1.0 A g(-1) 下表现出 945 F g(-1) 的高比电容。此外，以Fe2O3-QDs-3D GF为阳极、3D分层多孔石墨烯（HPG）为阴极制备了高性能非对称超级电容器，在0.40 kW kg(-1)功率密度和492.3 kW kg(-1)功率密度下表现出77.7 W h kg(-1)的极高能量密度，以及优异的循环稳定性。
A composite consisting of well-dispersed and ultrafine hematite quantum-dots (similar to 2.7 nm) anchored on a three-dimensional ultra-porous graphene-like framework (denoted as Fe2O3-QDs-3D GF) has been designed by a facile and scalable strategy. In the composite, the ultra-porous 3D GF with high conductivity and high surface area was used as a conductive matrix with surface defective sites for the controllable growth of uniformly dispersed, ultra-small Fe2O3-QDs. The graphene framework can tightly hold a great amount of Fe2O3-QDs, thereby ensuring high utilization of active materials and the required conductivity to individual Fe2O3-QDs. The ultra-small-sized Fe2O3-QDs anchored on the 3D GF can endow the composite with a superior high surface area and enough active sites for electrochemical reactions, thus giving the composite a large specific capacitance. As expected, the as-prepared Fe2O3-QDs-3D GF electrode exhibited a high specific capacitance of 945 F g(-1) at 1.0 A g(-1) in a three-electrode system in 2.0 mol L-1 KOH aqueous solution. In addition, high-performance asymmetric supercapacitors have been fabricated with Fe2O3-QDs-3D GF as the anode and 3D hierarchical porous graphene (HPG) as the cathode, and they showed a very high energy density of 77.7 W h kg(-1) at a power density of 0.40 kW kg(-1) and maximum power density of 492.3 kW kg(-1), as well as excellent cycling stability.