Altered Electrode Kinetics and Reactivity at the Nanoscale

It has been observed for silver nanoparticles that and a values are altered at nanoelectrodes from their values for the bulk material, as is the case for 4-nitrophenol reduction in water, as compared to the reaction at bulk silver (F.W. Campbell et al, ChemPhysChem. 11 (2010) 2820]. 

Further, the electrochemistry may be entirely changed, such as the altered mechanism of peroxide reduction in acidic media between nanoparticles and bulk material [F.W. Campbell etal.,J. Phys. Chem. C 113 (2009) 9053]. 

Where the surface structure of a nanoparticle differs from the bulk material, different adsorption kinetics are expected. This can be sufficient to alter the mechanism of a reaction where adsorption is significant, such as the reduction 

In fact, nanoparticles often cluster, rather than distributing in a perfectly random manner. An alteration to the distribution used in weighting different diffusion domains may be able to account for this. It is necessary to examine the electrode by a surface sensitive technique such as STM or AFM in order to accurately assess the distribution and coverage of nanoparticles, and hence to accurately describe the diffusional regime. 

---