Nano-Electrochemistry of Fluidized Particles: Solid State Reduction of ZnO Nano-Particles

Abstract

Electrochemical processes traditionally involve the reduction and oxidation of individual ions. Nano-electrochemistry is proposed and tested here, where nano-particles act as reactants and products and subsequently the electrochemical solid state reaction occurs within the nano-particles. The reduction of insoluble ZnO nano-particles is chosen as an example. The convective transport of the nano-particles to the current collector (rotating disk electrode) determines the rate of the solid state ZnO reduction to Zn. It is shown that once the fluidized particle touches the electrode, electrons are initially transferred from the current collector to the particle until the electrostatic potential is equilibrated, to be followed by solid state reduction within the nano-particles. SEM reveals the existence of partially reduced ZnO nano-particles. Electrochemistry of fluidized particles is starting to find applications in lithium ion batteries and flow redox batteries.