IN-SITU ELECTROCHEMICAL ACTINOMETRY USING AN AZO MONOLAYER FILM

We previously proposed an in-situ electrochemical actinometric techniq ue. It was established on the photoelectrochemical properties of azobe nzene derivatives in the assembled monolayer film where incident photo n number can be calculated from the faradaic charge quantity which flo ws during the fight irradiation. Here, we show that the light intensit y can be estimated more directly from the saturation current of cathod ic reaction in the above azobenzene monolayer system. When the actinom etric light is irradiated at a cathodic potential, azo molecules under go trans to cis isomerization and selective reduction of cis isomer oc curs simultaneously. The linearity between light intensity and cathodi c current was derived theoretically and examined experimentally. This allows simpler in-situ measurements of light intensity in photochemica l and photoelectrochemical experiments.