The effect of reduced graphene oxide on microstructure and thermoelectric properties of Nb-doped A-site-deficient SrTiO3 ceramics
The effect of reduced graphene oxide on microstructure and thermoelectric properties of Nb-doped A-site-deficient SrTiO3 ceramics
复制标题
还原氧化石墨烯对Nb掺杂A位缺陷SrTiO3陶瓷微观结构和热电性能的影响
DOI：
10.1016/j.jallcom.2019.01.376
复制
发表时间：
2019
影响因子：
6.2
通讯作者：
Jiang Wan
中科院分区：
文献类型：
--
作者：
Wu Cao;Li Jia;Fan Yuchi;Xing Juanjuan;Gu Hui;Zhou Zhenxing;Lu Xiaofang;Zhang Qihao;Wang Lianjun;Jiang Wan
SrTiO 3基陶瓷作为一种高温稳定性好的热电材料，虽然热电优值较低，但仍受到广泛关注。为了提高热电性能，还原氧化石墨烯（RGO）被成功地纳入Nb掺杂的SrTiO 3（STNO）陶瓷与Sr不足，通过异质聚集策略，然后退火和放电等离子烧结。RGO的加入通过还原效应提高了载流子浓度，并可能通过降低晶界处的双肖特基势垒提高了载流子迁移率，从而大大提高了复合材料的电导率。此外，RGO还促进了富Nb的TiO 2相的分离，其作为具有低热导率的分散体来抑制复合材料中的声子输运。因此，在800 K的RGO/STNO纳米复合材料的ZT值达到0.22，这是1.8倍，高于单片STNO。
As promising thermoelectric materials with great stability at high temperature, SrTiO3based ceramics have attracted much attention, albeit the thermoelectric figure of merit remains relatively low for application. To improve the thermoelectric properties, reduced graphene oxide (RGO) is successfully incorporated into Nb-doped SrTiO3(STNO) ceramics with Sr deficiency via a hetero-aggregation strategy followed by annealing and spark plasma sintering. The addition of RGO enhances the carrier concentration via reduction effect and increases the carrier mobility probably through lowering the double Schottky barrier at grain boundaries, resulting in highly improved electrical conductivity for the composites. Moreover, RGO also stimulates the separation of Nb rich TiO2phase, which serves as a dispersion with low thermal conductivity to prohibit the phonon transport in the composites. Consequently, a ZT value reaching 0.22 at 800 K for the RGO/STNO nanocomposite is obtained, which is 1.8 times higher compared with the monolithic STNO.