PPP Addition to Improve Thermoelectric Properties of ZnO-based Thermoelectric Composites

doi:10.15541/jim20160118

Abstract

Abstract:

PPP@Zn_1-_xCo_xO (x=0, 0.025) nanocomposites were prepared by Sol-Gel method, then bulk samples were prepared by spark plasma sintering. And thermoelectric properties of the samples were studied. Transmission electron microscopy (TEM) observations indicate that PPP nanoparticles are smaller than 200 nm. With the increase of PPP content, Seebeck coefficient gradually increases at first and then decreases, while electric conductivity increases quickly. Compared with ZnO bulk samples, the thermal conductivity of PPP@Zn_1-_xCo_xO nanocomposite is decreased. The thermal conductivity of 9wt% PPP@Zn_0.975Co_0.025O is decreased to 5.4 W/(m·K) at 640 K. The increase of electrical conductivity and the decrease of thermal conductivity resulted in a great increase in the value of thermoelectric properties. 9wt% PPP@Zn_0.975Co_0.025O has a maximal ZT value of 0.16 at 870 K, which is 8 times of that of Zn_0.975Co_0.025O bulk material.

Key words: ZnO, thermoelectric property, Sol-Gel, molecular junction

CLC Number:

TB34

WU Zi-Hua, XIE Hua-Qing, WANG Yuan-Yuan, MAO Jian-Hui, XING Jiao-Jiao, LI Yi-Huai. PPP Addition to Improve Thermoelectric Properties of ZnO-based Thermoelectric Composites[J]. Journal of Inorganic Materials, 2016, 31(11): 1249-1254.

Figures/Tables 5

Fig. 1 XRD patterns of Zn1-xCoxO sample

Fig. 2 TEM images of PPP@Zn1-xCoxO samples(a) Zn0.975Co0.025O; (b) 5wt% PPP@Zn0.975Co0.025O; (c) 9wt% PPP@Zn0.975 Co0.025O; (d) HRTEM image of 9wt% PPP@Zn0.975Co0.025O

Fig. 3 FTIR spectrum and TG-DSC curve of polyparaphenylene

Fig. 4 Temperature dependence of electronic properties and thermal conductivity of PPP@Zn1-xCoxO sample

Fig. 5 ZT of PPP@Zn1-xCoxO sample

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