Evidence for the adsorption of ion pairs on carbon surface by XANES spectroscopy

Synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy was used to characterize the adsorbed dicyanoargentate (I) species on the surface of nanoporous carbon. The speciation of the adsorbed dicyanoargentate (I) complexes was determined based on the nitrogen K → π∗ transition energy from XANES measurements. Clear evidence has been obtained for the adsorption of K + Ag ( CN ) 2 - ion pairs as dominant silver cyanide species while a minority of the dicyanoargentate (I) was adsorbed as unpaired Ag ( CN ) 2 - ions species.