Strontium titanate-based ceramics are promising n-type thermoelectrics due to their low cost and high thermal and chemical stability. Here, SrTiNbO was prepared with carbon additions of electrochemically produced graphene oxide (eGO) and commercially available carbon black (CB). Ceramic samples were sintered at 1700 K under a reducing atmosphere. XRD, HR-TEM and Raman spectra confirmed the matrix phase was cubic perovskite; there were no carbon residues. By incorporating graphene oxide, the electrical conductivity increased nine-fold to 2818 S cm at 300 K as a result of enhanced carrier mobility. In contrast, the carbon black samples exhibited low density and a small average grain size of ∼1 μm. High-resolution X-ray photoelectron spectroscopy revealed the presence of a large number of ionised impurities in the carbon black samples, which significantly enhanced scattering effects; low thermal conductivities of 1.7 W m K were achieved at 873 K. The work reveals that eGO promotes charge transport in SrTiO, while CB significantly suppresses phonon transport. Both effects are relevant to the development of other thermoelectrics.

中文翻译：

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氧化石墨烯和炭黑对铌掺杂钛酸锶热电性能的影响

钛酸锶基陶瓷由于其低成本和高热稳定性和化学稳定性而成为有前途的n型热电材料。在这里，SrTiNbO 是通过添加电化学生产的氧化石墨烯 (eGO) 和市售炭黑 (CB) 的碳来制备的。陶瓷样品在还原气氛下于 1700 K 下烧结。 XRD、HR-TEM和拉曼光谱证实基体相为立方钙钛矿；没有碳残留物。通过掺入氧化石墨烯，由于载流子迁移率增强，电导率在 300 K 下增加了九倍，达到 2818 S cm。相比之下，炭黑样品的密度较低，平均粒径较小，约为 1 μm。高分辨率X射线光电子能谱显示炭黑样品中存在大量电离杂质，这显着增强了散射效应；在 873 K 时实现了 1.7 W m K 的低热导率。该工作表明，eGO 促进 SrTiO 中的电荷传输，而 CB 显着抑制声子传输。这两种效应都与其他热电材料的发展相关。