Non-destructive deposition and diffusion–aggregation of size-selected silver nanoclusters on glassy carbon substrates as probed by real-time X-ray photoelectron spectroscopy

Silver nanoclusters, generated and size-selected in the gas phase and soft landed on low-temperature glassy carbon substrates, were characterized by real-time X-ray photoelectron spectroscopy (XPS). It has been found that the 3d core–electron binding energies of the deposited clusters gradually decrease with time in size-specific manners. The observation clearly showed that the clusters are deposited intact on the surface and diffuse and aggregate, leading to larger clusters. This demonstrates that the real-time XPS can provide key information on states and behaviors of size-selected nanoclusters deposited on surfaces.