Effects of surface passivation and interfacial reaction on the size-dependent 2p-level shift of supported copper nanosolids

Effects of surface passivation and particle-substrate interfacial reaction on the size dependent 2p_3/2-level shift of nanosolid Cu have been numerically analyzed, leading to information about the reactivity of Cu nanosolid with different substrates, such as graphite, polymer and alumina. It has been found that Ar⁺ bombardment promotes the Cu-polymer reaction and N⁺ passivation strengthens the surface bond due to nitride formation. Cu atom interacts with alumina slightly stronger at room temperature than at 80 K. Matching predictions to the measured size-dependent Cu-2p level shift reveals that the intra-atomic trapping energy of a core electron at the Cu 2p_3/2-level is -931.0 eV and the bulk crystal bonding intensity to the 2p_3/2 electron is -1.70 eV, which is beyond the scope of conventional approaches.