Highly Conductive Few-Layer Graphene/Al2O3 Nanocomposites with Tunable Charge Carrier Type
Highly Conductive Few-Layer Graphene/Al2O3 Nanocomposites with Tunable Charge Carrier Type
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具有可调电荷载流子类型的高导电性少层石墨烯/Al2O3纳米复合材料
DOI：
10.1002/adfm.201200632
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发表时间：
2012-09-25
影响因子：
19
通讯作者：
Kawasaki, Akira
中科院分区：
文献类型：
--
作者：
Fan, Yuchi;Jiang, Wan;Kawasaki, Akira
介绍了一种无表面活性剂辅助下非原位制备氧化石墨烯/金属氧化物杂化材料的方法。在此策略的指导下，采用两种滴定方法制备了GO/Al_2O_3杂化材料，其中GO和Al_2O_3胶体分别作为低和高GO含量杂化材料的滴定剂。采用放电等离子烧结法制备了几层石墨烯(FG)/Al_2O_3纳米复合材料，同时GO被很好地还原为FG。当FG含量仅为2.35%时，FG/Al_2O_3复合材料的渗流阈值可达0.38%，电导率超过103Sm-1，表现出FG的均匀分散和高质量。此外，发现随着石墨烯含量的增加，载流子类型由p型转变为n型。结果表明，这种转换与Al_2O_3基质的掺杂效应有关，并且与FG的厚度有关。
An ex situ strategy for fabrication of graphene oxide (GO)/metal oxide hybrids without assistance of surfactant is introduced. Guided by this strategy, GO/Al2O3 hybrids are fabricated by two kinds of titration methods in which GO and Al2O3 colloids are utilized as titrant for hybrids of low and high GO content respectively. After sintered by spark plasma sintering, few-layer graphene (FG)/Al2O3 nanocomposites are obtained and GO is well reduced to FG simultaneously. A percolation threshold as low as 0.38 vol.% is achieved and the electrical conductivity surpasses 103 Sm-1 when FG content is only 2.35 vol.% in FG/Al2O3 composite, revealing the homogeneous dispersion and high quality of as-prepared FG. Furthermore, it is found that the charge carrier type changes from p- to n-type as graphene content becomes higher. It is deduced that this conversion is related to the doping effect induced by Al2O3 matrix and is thickness-dependent with respect to FG.