Here we report on the production of an Ag 2 SO 4 /Ag 2 O mixed-grain powder during the anodization of Ag foil in a HF-H 2 SO 4 electrolyte. We propose that there are three competing reactions during the anodization process: (i) the production of Ag 2 O at the Ag foil anode surface from the presence of water in the electrolyte, (ii) the dissolution of the Ag 2 O in the presence of HF releasing Ag + ions, (iii) the precipitation of Ag + and SO 4 2- ions, as Ag 2 SO 4 on the Ag foil anode surface. This co-precipitation/dissolution process ultimately results in a mixed-grain powder. We then show that the Ag 2 O embedded within the mixed-grain is photo-decomposed to produce highly fluorescent silver nanoclusters (Ag n ) which decorate the Ag 2 SO 4 crystals. The Ag 2 SO 4 salt offers a stable matrix for the photo-decomposed Ag n nanoclusters to emit their strong fluorescence.
- Silver nanoclusters
- Silver sulphate/silver oxide mixed-grain powder