SnO2 nanograins Au-doped: A quantum mechanical evaluation of CO adsorption

In this study an analysis is made of the adsorption properties of nanocrystalline SnO₂ containing a metallic dopant. The analysis is based on semi-empirical Hartree–Fock and scattering theories and the structures considered are SnO₂ grains, with a rutile lattice, whose size and shape are comparable with the nanograins and nanowires produced in experiments. The grains contain rows of gold atoms located externally, on the grain surface, or in an endohedral position, in the grain interior, and the adsorbed system is generated by depositing CO molecules on the grain surface. The calculations illustrate the dependence of the binding energies and of the conductance on the grain size and on the location of the metallic additives in both the clean and in the CO-adsorbed grains. These results show that adsorption and current transport are determined by the intrinsic electronic structure of the adsorbing grains.