Nano-objects synthesized from Cu, Ag and Cu28Ag72 electrodes by submerged discharges in liquid nitrogen

Abstract

Discharges in liquid nitrogen between 2 electrodes made of either Cu, Ag or Cu28Ag72 enable the production of several types of comparable nano-objects. First, Cu nanoparticles (NPs) with sizes close to 5±4 nm nm and 40±10 nm are obtained with Cu electrodes and get oxidized in the air to form CuO after liquid evaporation. With Cu28Ag72 electrodes, copper contains a small amount of silver that inhibits oxidation. Next, silver nanoparticles are spherical but when doped with copper, they are facetted. Silver-containing nanowires have very similar features whether they are synthesized with silver or CuAg electrodes. They are made by assembly of NPs. Ag nanosheets are either single crystals in the case of CuAg electrodes or assembly of NPs in the case of silver electrodes. Finally, silver nanorods with traces of copper are only found with CuAg electrodes.Time-resolved optical emission spectroscopy indicates that the optical thickness decreases when copper is added to silver, lines appearing immediately after breakdown and not only after emission of a broad continuum. Emission of lines belonging to the N II system is then observed. The energy deposited being nearly constant, the structure of the discharge is assumed to be changed.

Synergistic Effect of Plasma and Laser Processes in Liquid for Alloyed-Nanoparticle Synthesis

“…Alloyed NPs are already observed after the sole plasma treatment unlike what had been reported for a pin-topin configuration, with electrodes made of pure Cu and Ag [41]. This shows some difference in the physical processes at stake when using powders rather than bulk electrode as the initial source material.…”

Preparation of Metal Nitride Particles Using Arc Discharge in Liquid Nitrogen

“…Irregular round-shaped particles were synthesized mainly in Ti 5 A, while most cubic morphology particles were observed in Ti 30 A. The cubic-shaped particle was reported as the crystal structure of TiN [ 39 , 40 , 41 ]. To confirm the component of cubic particles, EDS elemental mapping was conducted during the FE-SEM observation.…”

“…As a product, they also obtained Al, Ti, V, Fe, Ni, Cu, Zr, Nb, Mo, Ta, and W micro-size particles using a DC power supply [ 36 ]. Belmonte et al also reported synthesizing Cu, Ag, Pb, CoNi, and ZnO nanoparticles using a nano-pulse power supply [ 30 , 37 , 38 , 39 , 40 , 41 , 42 ]. Sano et al presented the synthesis of Pt-supported carbon nanohorns for fuel cell electrodes [ 43 ].…”

Study by Optical Spectroscopy of Bismuth Emission in a Nanosecond-Pulsed Discharge Created in Liquid Nitrogen

“…Processes based on discharges in liquids are commonly used to synthesize original nanoobjects with high yields [ 1 , 2 , 3 , 4 , 5 ]. In liquid nitrogen, they are particularly interesting, as they lead to the synthesis of two-dimensional structural materials like nanosheets [ 6 , 7 , 8 ], exhibiting high levels of selectively exposed reactive facets and the fast separation of electrons and holes.…”