Direct evidence for electric field assisted dissolution of Au nanoparticles on glass surface

Spherical gold (Au) nanoparticles are formed onto glass surface by sputtering of Au foil and the following annealing process. By employing electric field assisted annealing of above as-prepared samples, the original spherical Au nanoparticles are dissolved to lunar-eclipselike structure and even fully dissolved. When applied voltages are increased in steplike feature, spikelike sharp current increase is observed at every voltage step, and it is followed by a rather long current decaying process. The spikelike current increase indicates the onset of electronic transport, leading to Au nanoparticles polarization and ionization. Long current decaying process is assigned to the electronic conduction from cathode to recombine with as-ionized positive charges, along with Au cationic transport resulting in dissolution of Au atoms from the nanoparticles. Our current study provides straightforward evidence of electric field assisted dissolution of Au nanoparticles on glass surface.