Surface chemistry and conduction in nano-composite thin films Seminar

Work reported in this presentation is on the preparation and investigation of nano-composite films. Materials prepared on the nanoscale have vastly different properties to that of the bulk. Of particular interest is conduction processes that are important as they have a direct comnsequnce of the chemistry investigated such as splitting water or molecular electronics.
Two nano-composite materials were evaluated, iron oxide and Ru-dimer coated TiO2 nanoparticles. In both cases the surface species of the nanoparticles can be investigated using electrochemical techniques.

For -Fe2O3 nanoparticles the surface states of Fe include the intrinsic Fe(III) as well as Fe(II) and what isa higher oxidation states of Fe. This higher oxidation state of iron is studied for the catalytic oxidation of glucose and water. Using spectro-electrochemical techniques such as potential modulated absorption spectroscopy and light modulated adsorption spectroscopy a spectra of the higher oxidation was recorded.

TiO2 nanoparticles were coated with a Ru-dimer. At the potentials explored the ruthenium oxidises from the Ru(II) state to the Ru(III). Diffusion coefficients were recorded for the movement of charges through the structure using two different techniques and a value of 1 x 10-15 m2 s-1 was recorded.