Theoretical prediction of a transient accumulation of nanoparticles at a well-defined distance from an electrified liquid–solid interface

The Brownian motion of nanoparticles near liquid-solid interfaces is at the heart of evolving technologies: recent developments in the sensing of nano-objects and energy storages based on electro-active colloidal solutions crucially rely on the understanding and, even more, on the control of particle transport near charged surfaces. On the basis of the Nernst-Planck equation, the Gouy-Chapman model, and an established model of near-wall hindered diffusion, this work predicts transient and highly-localised accumulations of nanoparticles at a well-defined distance from an electrified surface following a potential being applied. The interplay of electrostatics and near-wall hindered diffusion yields entirely unexpected effects: nanoobjects temporarily accumulate near the interface while even small electric potentials applied at the surface can dramatically enhance the mass transport of nano-objects towards it.