A simple plasma reduction for synthesis of Au and Pd nanoparticles at room temperature

A simple and fast plasma reduction method is developed for synthesis of Au and Pd metal nanoparticles. The scanning electron microscopy (SEM) analysis indicates a formation of aggregates of Au and Pd nanoparticles with branched structure. The transmission electron microscopy (TEM) image shows that the inclusive nanoparticles are all about 5 nm in size. Compared to conventional hydrogen reduction method, plasma method inhibits the agglomeration of metal particles. The room temperature operation is very helpful to limit the nanoparticle size. Most interestingly, plasma reduction produces more flattened metal particles. This plasma reduction does not require the use of any hazardous reducing chemicals, showing the great potential for the fabrication of noble metal nanoparticles.

Graphical AbstractThe simple and fast argon glow discharge plasma reduction is conducted at room temperature, which is very helpful for the nanoparticle size control. We proposed that the mechanism of plasma reduction may be related to two processes. One is a direct process. The high energy electrons generated by the plasma most likely serve as the reducing agents. When the glow discharge reducible metal ions are immersed in the plasma zone, electrons will move towards the metal ions due to the electrostatic attraction.Figure optionsDownload full-size imageDownload as PowerPoint slide