Local quantum size effect as seen by room-temperature 195Pt NMR in octanethiol-protected Pt nanoparticles

The average energy level spacing δ at the Fermi level has been almost exclusively used as a global indicator for predicting quantum size effect in metal nanoparticles and its detailed local characteristics have usually been neglected. Here, we report new 195Pt NMR evidence obtained on octanethiol-protected Pt nanoparticles with an average particle size of 1.0 ± 0.3 nm at room temperature which shows that the local characteristics of δ can be discerned and are directly related to the local variations of electronic properties of the system in its ‘bulk’ metallic state.