Here, we present our current attempt to intrinsically dope Ni⁰, Co⁰, and Fe⁰ nanoparticles within Ni^II-, Co^II-, and Fe^II-borate glassy matrices, respectively. The system was prepared by one-pot reaction of the desired M_T^II salt with excess NaBH₄ through an in-situ reduction and hydrolysis processes to afford metallic M_T⁰ nanoparticles dispersed into the M_T-BO₃ matrix. The composition and structural characteristics of these M_T⁰:M_T-BO₃ materials were identified by thermal oxidation, ATR-IR, X-ray powder diffraction, and magnetic techniques as glassy/amorphous borate matrices containing magnetic nanoparticles. The electrical conductivity (σ) of cold-pressed discs of these metal-doped composites shows that they behave as nonohmic semiconductors within the temperature range of 303 ≤ T ≤ 373 K suggesting a mixed electronic-ionic conduction. However, their thermal conductivity (κ) occurs through phonon lattice vibration dynamics rather than electronic. The σ/κ ratio shows a steep non-linear increase from 9.4 to 270 KV⁻² in Ni⁰:Ni-BO₃. In contrast, a moderate-weak increase is observed for Co⁰:Co-BO₃ and Fe⁰:Fe-BO₃ analogs. The obtained materials are examined for thermoelectric (TE) applications by determining their Seebeck coefficient (S) power factor (PF), figure of merit (ZT), and conversion efficiency (η%). All the TE data shows that Ni⁰:Ni-BO₃ (S, 80 μVK⁻¹; PF, 97.7 mWm⁻¹ K⁻¹; ZT 0.54; η, 2.15%) is a better TE semiconductor than the other two M_T⁰:M_T-BO₃. This finding shows that Ni⁰:Ni-BO₃ is a promising candidate to exploit low-temperature waste heat from body heat, sunshine, and small domestic devices for small-scale TE applications.

中文翻译：

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掺入其金属硼酸盐玻璃态基质中的 Ni、Co 和 Fe 纳米粒子的热电性能

在这里，我们展示了我们目前的尝试，分别在 Ni ^II -、Co ^II - 和 Fe ^II -硼酸盐玻璃基体中本质掺杂 Ni ⁰、Co ⁰和 Fe ^{0纳米颗粒。}_{该系统是通过所需的 M T} ^II盐与过量的 NaBH ₄通过原位还原和水解过程进行一锅法反应制备的，以提供分散到 M _T -BO ₃基质中的金属 M _T ^{0纳米颗粒。}这些M _T ⁰ :M _T -BO _{3的组成和结构特征}材料通过热氧化、ATR-IR、X 射线粉末衍射和磁性技术鉴定为含有磁性纳米颗粒的玻璃态/非晶态硼酸盐基质。这些金属掺杂复合材料的冷压圆盘的 电导率 ( σ ) 表明它们在 303 ≤ T  ≤ 373 K 的温度范围内表现为非欧姆半导体，表明混合电子-离子传导。然而，它们的热导率 ( κ ) 通过声子晶格振动动力学而不是电子发生。σ / κ比率显示Ni ⁰ :Ni-BO _{3中从 9.4 到 270 KV} ^-2的急剧非线性增加. 相反，对于Co ⁰ :Co-BO ₃和Fe ⁰ :Fe-BO ₃类似物观察到中度-弱增加。通过确定塞贝克系数 ( S ) 功率因数 (PF)、品质因数 (ZT) 和转换效率 ( η %) ，对获得的材料进行热电 (TE) 应用检查。所有 TE 数据表明 Ni ⁰ :Ni-BO ₃ ( S , 80 μVK ^-1 ; PF, 97.7 mWm ⁻¹  K ⁻¹ ; ZT 0.54; η , 2.15%) 是比其他两种 M _{T更好的 TE 半导体}⁰ :M _T -BO ₃. 这一发现表明，Ni ⁰ :Ni-BO ₃是一个很有前途的候选者，可以利用体热、阳光和小型家用设备的低温废热，用于小型 TE 应用。