Among the state-of-the-art thermoelectric materials, copper sulfides (Cu₂S) have been predicted as promising thermoelectric materials due to their low intrinsic thermal conductivity. However, they still confront the problems with lower electrical properties, which distinctly restrict their thermoelectric application. Significant enhancement of thermoelectric properties is a great challenge owing to the common interdependence of electrical and thermal conductivity. Herein, a micro/nano Cu_2-xS composite, with significantly enhanced thermoelectric properties, is prepared via a simple hydrothermal method. Due to the synergistic effect of the introduced nanostructure and the increased Cu_1.96S contents, the micro/nano Cu_2-xS bulk samples present a power factor of 10.1 μW cm⁻¹ K⁻² at 773 K. Meanwhile, a decrease of the thermal conductivity to 0.69 W m⁻¹ K⁻¹ is obtained, originating from the strong phonon scattering of micro/nano structure. Remarkably, a ZT_max value of 1.1 at 773 K is obtained, which is higher than the reported Cu_2-xS thermoelectric material using chemical methods. This study proposes a facile microstructure engineering strategy for the development of high-performance thermoelectric materials.

在最先进的热电材料中，硫化铜（Cu ₂ S）由于其低固有热导率而被预测为有前途的热电材料。然而，它们仍然面临着电性能较低的问题，这明显限制了它们的热电应用。由于电导率和热导率的共同相互依赖性，显着提高热电性能是一个巨大的挑战。在此，通过简单的水热法制备了具有显着增强的热电性能的微/纳米Cu _{2-x S 复合材料。}由于引入的纳米结构的协同效应和增加的Cu _1.96 S含量，微/纳米Cu _2-xS 块状样品在 773 K 时的功率因数为 10.1 μW cm ^-1 K ^-2。同时，由于微/纳米的强声子散射，热导率降低至 0.69 W m ^-1 K ^-1结构体。值得注意的是，在 773 K 时获得了 1.1 的ZT_最大值，这高于使用化学方法报道的 Cu _2-x S 热电材料。本研究为开发高性能热电材料提出了一种简便的微结构工程策略。