Construction of a 3D-rGO network-wrapping architecture in a YbyCo4Sb12/rGO composite for enhancing the thermoelectric performance
Construction of a 3D-rGO network-wrapping architecture in a YbyCo4Sb12/rGO composite for enhancing the thermoelectric performance
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DOI：
10.1039/c5ta01594d
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发表时间：
2015-04
影响因子：
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通讯作者：
Peng‐an Zong;Xi-hong Chen;Yanwu Zhu;Ziwei Liu;Yi Zeng;Lidong Chen
中科院分区：
文献类型：
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作者：
Peng‐an Zong;Xi-hong Chen;Yanwu Zhu;Ziwei Liu;Yi Zeng;Lidong Chen
纳米结构和纳米复合材料在降低晶格热导率和改善热电材料性能方面已被证明是有效的。然而，由于难以在增加颗粒含量的同时保持均匀而狭窄的粒度分布，纳米颗粒分散对ZT的增强作用仅限于一个有限的水平。在本研究中，以氧化石墨烯（GO）为前驱体，通过简单的原位还原方法制备了基于ybyco4sb12的纳米复合材料，该复合材料在晶界基质上嵌入了几纳米的还原氧化石墨烯（rGO）层，形成了三维网络。3D-rGO网络包裹结构由于粒子间和粒子内声子散射效应的增强而显著降低了晶格热导率，同时由于纳米厚度的晶界半导体rGO层的能量滤波效应而提高了塞贝克系数。Yb0.27Co4Sb12/rGO （0.72 vol%）复合材料在850 K下的ZT最大值为1.51，优于所有单填充的skutterudites及其纳米复合材料。
Nanostructures and nano-composites have been shown to be effective in depressing the lattice thermal conductivity and improving the performance of thermoelectric materials. However, ZT enhancement by nano-particle dispersion is limited only to a restricted level due to the difficulty in increasing the particle contents while maintaining a uniform and narrow size distribution. In the present work, YbyCo4Sb12-based nano-composites with reduced graphene oxide (rGO) layers of several nanometers intercalated on the grain boundary matrix forming a 3D network have been prepared through a simple in situ reduction approach using graphene oxide (GO) as the precursor. The 3D-rGO network wrapping architecture dramatically reduced the lattice thermal conductivity due to enhanced interparticle and intraparticle phonon scattering effects, and simultaneously enhanced the Seebeck coefficient due to the energy filtering effect of the grain boundary semiconductive rGO layer with nanometer thickness. The maximum ZT value of 1.51 was achieved for the Yb0.27Co4Sb12/rGO (0.72 vol%) composite at 850 K, outperforming all single-filled skutterudites and their nanocomposites ever reported.