Atomic force microscopy of cubic Pt nanoparticles in electrochemical environments

Real structure of cubic Pt nanoparticle has been studied at various potentials in 0.1 M NaClO₄ with the use of atomic force microscopy (AFM). Cubic Pt nanoparticles in 10 nm height are clearly imaged from 0.10 V to 1.10 V (Ag/AgCl). The height of the nanoparticle increases 1.2 ± 0.7 nm (10.4 ± 6.8%) around the onset potential of oxygen evolution (1.20 V (Ag/AgCl)). The height increase is attributed to the formation of the oxide species at the inner layers of the nanoparticle. Dissolution of the nanoparticle starts from the upper terrace, not from the edge above 1.40 V (Ag/AgCl).