Silver and gold nanoparticles were produced using the pinhole discharge generated by dc non-pulsing high voltage directly in a precursor solution. Silver nitrate solution was used as the precursor for silver nanoparticles, and chloroauric acid was used as the precursor for gold nanoparticles. Effects of discharge time, precursor concentration, and additives such as reduction agent (ethylene glycol) and capping agent (polyethylene glycol and sucrose) were studied. Nanoparticles were mainly analyzed by UV-VIS spectrometry. The size of prepared nanoparticles was determined by the dynamic light scattering with backscattering detection. To determine the stability of nanoparticles, the zeta potential was measured by the electrophoretic light scattering. It was found that the absorption maximum of nanoparticles increases with the time of the discharge treatment and concentration of the precursor. The size of silver nanoparticles ranged from 10 to 1000 nm and the final solution had higher polydispersity. The size of Au nanoparticles ranged from 10 to 100 nm, depending on the precursor concentration. The most stable particles were prepared from the pure precursor solution without any additives. The addition of ethylene glycol stimulated the reduction process of nanoparticles from the solution but it decreased their zeta potential. Final particles were less stable, which started to form larger structures that tended to sediment. Added capping agent decreased the input of power needed for the stable discharge operation. The formation of silver and gold nanoparticles was confirmed by scanning electron microscopy with the energy dispersion spectrometer. Both silver and gold particles had spherical shapes.

中文翻译：

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针孔直流等离子体系统制备银和金纳米粒子

使用由直流非脉冲高压直接在前体溶液中产生的针孔放电产生银和金纳米颗粒。硝酸银溶液用作银纳米颗粒的前驱体，氯金酸用作金纳米颗粒的前驱体。研究了放电时间、前体浓度和添加剂如还原剂（乙二醇）和封端剂（聚乙二醇和蔗糖）的影响。纳米颗粒主要通过紫外-可见光谱法进行分析。制备的纳米颗粒的尺寸通过动态光散射和背向散射检测来确定。为了确定纳米颗粒的稳定性，通过电泳光散射测量 zeta 电位。发现纳米粒子的吸收最大值随着放电处理时间和前体浓度的增加而增加。银纳米粒子的尺寸范围为 10 到 1000 nm，最终溶液具有更高的多分散性。Au 纳米粒子的大小范围为 10 到 100 nm，具体取决于前体浓度。最稳定的颗粒是从纯前体溶液中制备的，没有任何添加剂。乙二醇的加入刺激了溶液中纳米颗粒的还原过程，但降低了它们的 zeta 电位。最终的颗粒不太稳定，开始形成更大的结构，倾向于沉淀。添加封端剂减少了稳定放电操作所需的功率输入。通过使用能量色散光谱仪的扫描电子显微镜确认银和金纳米颗粒的形成。银和金颗粒均具有球形形状。