Energetic electrochemiluminescence of (9-fluorenyl)methanol induced by injection of hot electrons into aqueous electrolyte solution

Hot electron injection into aqueous electrolyte solutions from metal/insulator/metal/electrolyte and metal/insulator/electrolyte tunnel junctions is considered and the possibility of an electrochemical generation of hydrated electrons is discussed. The hot electron-induced UV electrochemiluminescence of (9-fluorenyl)methanol was used to demonstrate the presence of highly energetic transient species in aqueous solution at several metal/insulator/electrolyte hot electron tunnel emitters. These transient species cannot be produced electrochemically in fully aqueous solutions at any active metal electrodes. A detailed mechanism for the present electrochemiluminescence is suggested.