0000000000542148
AUTHOR
Elisabet Ahlberg
Convective mass transfer to partially recessed and porous electrodes
Abstract The diffusional problem of a rotating porous electrode has been analysed based on the mass transfer equations for a partially blocked electrode. It is shown that the porous geometry leads to a dependence of the current on rotation rate identical to that corresponding to a coupled diffusion-activated electron transfer mechanism. The apparent rate constant, however, is related only to the geometry of the porous surface. It is shown that the characteristic diffusional length corresponds to the pore dimension modified by a term including the transition from linear to spherical diffusional geometry at the pore entrance. The theory is compared with experimental results for the reduction …
Size dependent surface charging of nanoparticles
International audience; Experimental interest in the possible curvature dependence of particle charging in electrolyte solutions is subjected to theoretical analysis. The corrected Debye−Hückel theory of surface complexation (CDH-SC) and Monte Carlo (MC) simulation are applied to investigate the dependence of surface charging of metal oxide nanoparticles on their size. Surface charge density versus pH curves for spherical metal oxide nanoparticles in the size range of 1−100 nm are calculated at various concentrations of a background electrolyte. The surface charge density of a nanoparticle is found to be highly size-dependent. As the particle diameter drops to below 10 nm there is considera…