Sonoelectrochemical (20 kHz) production of Co65Fe35 alloy nanoparticles from Aotani solutions

Abstract

This paper describes the production of alloy nanoparticles of Co:Fe ratio 65:35 from Aotani solutions in the presence of high power ultrasound (20 kHz). The production of this new type of alloy nanoparticles was performed potentiostatically and galvanostatically at (298 ± 1) K using a newly designed experimental set-up i.e. a 'sonoelectrode' producing short applied current pulses triggered and followed immediately by ultrasonic pulses. It was shown that cathode efficiencies decreased with increasing current densities and high nanoparticle yields were obtained at low current densities. Morphological and structural studies of the produced nanoparticles were performed by TEM, SEM, XRD, and SAED, and showed that the strongly aggregated Co 65 Fe 35 alloy nanoparticles were predominantly formed, with prevalent bodycentered cubic bcc crystalline structure; no redissolution of the nanoaggregates was observed and no separate Fe and Co metallic nanoparticles were produced sonoelectrochemically. The experimental value of the lattice parameter for bcc Co-Fe alloy was 2.85 Å and was in excellent agreement with literature values.

Sonoelectrochemical Synthesis of Nanoparticles

“…This new electrochemical method has since been employed to produce numerous pure metals [ 32 , 36 , 37 ] or alloys nanopowders [ 38 , 39 ] and semiconductor nanoparticles [ 40 ]. More recently, conductive polymer nanoparticles [ 41 ] have also been synthesized by pulsed sonoelectrochemistry.…”

The Use of Power Ultrasound for the Production of PEMFC and PEMWE Catalysts and Low-Pt Loading and High-Performing Electrodes

“…Dabalà et al [21] demonstrated the production of nanoparticles by sonoelectrochemistry as the technique offers many advantages: (i) great enhancement in mass-transport near the electrode, thereby altering the rate, and sometimes the mechanism, of the electrochemical reactions; (ii) modification of surface morphology through cavitation jets at the electrode-electrolyte interface, usually causing an increase of the surface area; and (iii) reduction of the electrode diffusion layer thickness and therefore ion depletion. Zin, Pollet, and Dabalà [22] modified Reisse's original setup by only using the vibrating tip of the ultrasonic probe as the cathode-'sonoelectrode', as shown in Figure 9.…”

“…Sonoelectrochemical setup for the production of PEMFC and PEMWE catalysts[17,21,22]. GC: Glassy carbon.…”

An Introduction to Sonoelectrochemistry

“…Pulsed sonoelectrochemical techniques [78] have been employed to produce numerous pure metals [79,80], alloys [81], semiconductors [82] and polymer nanoparticles [83]. The particular attributes of metal powders obtained using this technology are that they are produced in a very finely divided state with high surface area, high chemical purity and with an average particle size of 100 nm [84].…”