Self-assembled three-dimensional hierarchical graphene hybrid hydrogels with ultrathin β-MnO2 nanobelts for high performance supercapacitors
Self-assembled three-dimensional hierarchical graphene hybrid hydrogels with ultrathin β-MnO2 nanobelts for high performance supercapacitors
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DOI：
10.1039/c4ta04921g
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发表时间：
2015
影响因子：
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通讯作者：
S. Zhu;Hui Zhang;Ping Chen;Lingfang Nie;Chuanhao Li;Shi-Kuo Li
中科院分区：
文献类型：
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作者：
S. Zhu;Hui Zhang;Ping Chen;Lingfang Nie;Chuanhao Li;Shi-Kuo Li
我们报道了一种通过水热反应将预合成的β-MnO 2纳米带（NB）分散在氧化石墨烯（GO）前体溶液中组装成分级和互连的还原氧化石墨烯/β-MnO 2（rGO/β-MnO 2）纳米带杂化水凝胶的简便方法。通过调节β-MnO 2纳米粒子的含量可以控制三维杂化水凝胶的微观结构，从而使其具有低密度、大比表面积和高压缩强度的特性。重要的是，含有54.2% β-MnO 2 NB的典型混合水凝胶在1.0 A g− 1的电流密度下显示出高达362 F g−1的比电容，甚至在20 A g−1下显示出282 F g−1的比电容，这是纯rGO水凝胶（118 F g−1）的三倍。同时，典型的杂化水凝胶也显示出出色的循环稳定性，在10000次循环伏安（CV）扫描后，电容保持率为96.3%。这些发现开辟了将纳米纤维用于混合水凝胶的自组装，作为能量储存和转换中的高性能超级电容器装置。
We report a facile method to assemble a hierarchical and interconnected reduced graphene oxide/β-MnO2 (rGO/β-MnO2) nanobelt hybrid hydrogel by dispersion of presynthesized ultrathin β-MnO2 nanobelts (NBs) in graphene oxide (GO) precursor solution by a hydrothermal reaction. The microscopic structure of the three-dimensional (3D) hybrid hydrogel can be controlled by adjusting the content of the ultrathin β-MnO2 NBs, which exhibits the properties of low density, large specific surface area, and high compressive strength for the corresponding aerogel. Importantly, a typical hybrid hydrogel with 54.2% ultrathin β-MnO2 NBs displays a specific capacitance as high as 362 F g−1 at a current density of 1.0 A g−1, and even 282 F g−1 at 20 A g−1, which is three times higher than that of the pure rGO hydrogel (118 F g−1). Meanwhile, the typical hybrid hydrogel also shows outstanding cycling stability with 96.3% capacitance retention after 10 000 cycles of cyclic voltammetry (CV) scans. These findings open up the use of ultrathin NBs for the self-assembly of hybrid hydrogels as high performance supercapacitor devices in energy storage and conversion.