Rotational diffusion current of multi-charged redox species by means of Monte Carlo simulation

Multi-charged redox species such as dispersed metal nanoparticles and latex particles have exhibited diffusion-controlled currents, which may be caused by not only the conventionally translational diffusion but also by the rotation of the species or random orientation toward the electrode. Rotational diffusion was here taken into account by use of the multiple redox-charged model particle which moves back and force in thin layer cell as well as rotates clockwise and counterclockwise by means of the Monte Carlo simulation. The steady-state current was smaller than the current which might flow if all the charge were to transfer at infinite rotational speed. The current values had a linear relation with the -1/2 powers of the number of the charge per particle. This relation was in accord with the experimental results of the partial charge transfer reaction of the ferrocene-immobilized latex suspension. (c) 2006 Elsevier Ltd. All rights reserved.