Zinc cobalt oxide (ZCO) nanoparticles and zinc cobalt oxide/polypyrrole (ZCO/PPy) nanocomposites were synthesized by hydrothermal and in situ chemical polymerization routes, respectively. X-ray diffraction (XRD) patterns of PPy and ZCO/PPy nanocomposites show the amorphous nature of PPy, while there is the presence of dominant crystalline peaks of ZCO in the PPy matrix. Field-emission scanning electron microscopy (FESEM) depicts a spherical geometry and shows a decrease in the particle size with an increase in the ZCO weight percentage, while the transmission electron microscopy (TEM) images depict the core–shell-type formation of particles with aggregated ZCO nanoparticles as a core embedded in the PPy shell. The Fourier transform infrared (FTIR) spectra of ZCO/PPy nanocomposites show all the asymmetrical stretching vibrations of PPy and ZCO along with an increase in intensities of the respective metal oxides peaks and slight shifts in a few bands. Further, the transport studies, i.e., direct current (DC) conductivities of the ZCO/PPy nanocomposites, were studied as a function of temperature (300–453 K) and reveal semiconducting transport behavior. The analysis of DC conduction in PPy and ZCO/PPy suggests that the conduction of charge carriers follows the three-dimensional Mott variable range hopping (3D-VRH) model at a lower temperature, while it follows a thermally activated conduction model at high temperature.

中文翻译：

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聚吡咯/氧化锌钴纳米复合材料的三维变程跳跃和热激活传导机理

水热法原位合成了氧化锌钴纳米颗粒和氧化钴/聚吡咯锌纳米复合材料化学聚合路线。PPy和ZCO / PPy纳米复合材料的X射线衍射（XRD）图谱显示PPy为非晶态，而在PPy基质中存在ZCO的主要结晶峰。场发射扫描电子显微镜（FESEM）描绘了球形几何形状，并显示出随着ZCO重量百分比的增加，粒径减小，而透射电子显微镜（TEM）图像描绘了核-壳型颗粒的形成。聚集的ZCO纳米颗粒作为嵌入PPy外壳的核。ZCO / PPy纳米复合材料的傅立叶变换红外（FTIR）光谱显示了PPy和ZCO的所有不对称拉伸振动以及相应金属氧化物峰强度的增加和在几个谱带中的轻微偏移。此外，运输研究，即 研究了ZCO / PPy纳米复合材料的直流电（DC）电导率与温度（300–453 K）的关系，并揭示了半导体的传输行为。对PPy和ZCO / PPy中DC传导的分析表明，电荷载流子的传导在较低温度下遵循三维Mott变程跳变（3D-VRH）模型，而在高温下遵循热激活传导模型。