Background: This study used Electrical Spark Discharge Method (ESDM) to fabricate the nano-Au, nano-Ag and nano-Cu colloid. The spark wears down the surface of the electrodes and gets nano-metal particles at standard temperature and pressure and without adding any other chemical materials in the deionized water.

Methods: The nano-metal particles are examined by UV-Visible Spectroscopy, Zetasizer, Transmission Electron Microscope, and Energy Dispersive X-ray Analysis and are proven to be nano-metal colloid. Under the comparison of different parameters (discharge pulse width, HV, Ip), the size of nano-metal particles increases with the level of Ip.

Results: Under the experiment of light or dark, most of the Absorbance of the nano-Au and nano-Ag colloid is higher than that of the environment under strong light irradiation as long as it is prepared in a pure black environment. The nano-Au and nano-Ag colloid prepared by ESDM have a zeta potential exceeding the absolute value of 30 mV, no matter which parameter is applied or whether there is illumination or not.

Conclusion: It represents a good suspension stability of the nano-Au and nano-Ag colloid, but the nano-Cu colloid does not have this feature. The suspension stability is not good.

背景：这项研究使用电火花放电法（ESDM）来制造纳米金，纳米银和纳米铜胶体。火花会磨损电极的表面，并在标准温度和压力下获得纳米金属颗粒，并且在去离子水中不添加任何其他化学材料。

方法：通过紫外-可见光谱，Zetasizer，透射电子显微镜和能量色散X射线分析法对纳米金属颗粒进行了检查，证明它们是纳米金属胶体。在不同参数（放电脉冲宽度，HV，Ip）的比较下，纳米金属颗粒的尺寸随Ip的水平而增加。

结果：在明亮或黑暗的实验下，只要是在纯黑色环境中制备，纳米金和纳米银胶体的大多数吸收率都比强光照射下的环境要高。由ESDM制备的纳米金和纳米银胶体，无论施加何种参数或是否有照明，其ζ电位都超过30 mV的绝对值。

结论：它代表了纳米金和纳米银胶体良好的悬浮稳定性，但纳米铜胶体不具有此特性。悬架稳定性不好。