Pure and copper doped cobalt sulphide (Co₉S₈) nanoparticles were synthesized using aqueous chemical co-precipitation method. To study the effect of elemental composition Cu (0%, 1%, 5%, 10%&15%) on structural, optical, electrical and thermoelectric properties of Co₉S₈ nanoparticles were investigated using various characterization techniques such as XRD, SEM, FTIR, UV-VIS and two probe methods. Cubic structure and grain size of pure and Cu doped Co₉S₈-NPs was confirmed by X-ray diffraction and SEM analysis. FTIR spectrum showed the different rotational and vibrational mode attached on the surface of the material. A redshift appeared in the band gap value (E_g) as a function of the Cu dopant and high absorbance in the optical region makes the material suitable for photocatalytic activity. The electrical result show that conductivity increases and resistivity decreased as Cu content increases in Co₉S₈-NPs. Finally, thermoelectric measurements referred to the unique critical temperature for each sample where current starts rising exponentially.

采用水化学共沉淀法合成了纯铜掺杂的硫化钴（Co ₉ S ₈）纳米颗粒。为了研究元素组成Cu（0％，1％，5％，10％＆15％）对Co ₉ S ₈纳米颗粒的结构，光学，电和热电性能的影响，采用了多种表征技术，例如XRD，SEM， FTIR，UV-VIS和两种探测方法。通过X射线衍射和SEM分析证实了纯的和掺杂Cu的Co ₉ S ₈ -NPs的立方结构和晶粒尺寸。FTIR光谱显示了附着在材料表面的不同旋转和振动模式。带隙值（E _g）作为Cu掺杂剂的函数，光学区域的高吸收率使该材料适合光催化活性。电学结果表明，随着Co ₉ S ₈ -NPs中Cu含量的增加，电导率增加而电阻率降低。最后，热电测量涉及每个样品的独特临界温度，电流开始以指数方式上升。