The magneto-electrochemistry of nanoparticles
To date, the exploitation of magneto-electrochemistry, combining fluid mechanics, electrochemistry and electromagnetism has been largely limited to macro- and micro-scales. Scientists initiated the IMAFECY (Impact of magnetic fields on electrochemistry – fundamental aspects and future applications) project with the aim of extending the applications to the nanoscale. To this end, the scientists investigated both theoretically and experimentally the effects of magnetic fields on the electrochemistry of nanoparticles. These materials have dimensions below 100 nanometres and are of scientific interest as their properties can be finely tuned by changing their size. They are also used in medical applications and a broad variety of consumer products. Through what are known as 'nano-impact' experiments, the scientists tracked for the first time the agglomeration of magnetic nanoparticles induced by the presence of magnetic fields. Moreover, the dissolution of paramagnetic nanoparticles was strongly inhibited. The scientists gained valuable new insights into this process using cathodic particle coulometry. The electrochemical technique for nano-impacts helped track metal nanoparticles in simple electrolytes. Their use was extended to enable IMAFECY scientists to study metal nanoparticles in aqueous media, like sea water, and to follow organic nanoparticles. Nano-impacts also provided information about physicochemical properties that were inaccessible by any other technique. The mass transport to and from individual nanoparticles and nanoparticles immobilised on an electrode was found to vary significantly. Together with numerical simulations, the scientists reasoned that the different mass transport could be behind changes in the reactivity of nanoparticles as compared to bulk materials. Combining experiment with theory in the IMAFECY project has significantly improved the current understanding of the interplay between various parameters involved in magneto-electrochemistry at the nanoscale. The first results have been presented in more than 30 papers published in peer-reviewed journals and at numerous international conferences.
Keywords
Magneto-electrochemistry, nanoparticle, nano-impact experiment, electrolyte, numerical simulation
