Highly efficient photoinduced electron transfer on a benzothiazolium styryl dye Langmuir–Blodgett monolayer modified-ITO electrode

An amphiphilic benzothiazolium styryl dye 2-(4-dihexadecylaminostyryl)benzothiazole methiodide (DBM) was synthesized and deposited on a conducting transparent indium–tin oxide (ITO) electrode in H-aggregates by using the Langmuir–Blodgett (LB) technique. Its photoelectrochemistry was investigated in a traditional three-electrode cell. Coincidence of its action spectrum and the absorption spectrum on the ITO indicated that DBM was responsible for the generation of the photocurrent. Under favorable conditions, its monolayer quantum yield can reach as high as 4.2%. A mechanism of photoinduced electron transfer in this system was proposed based on the experiments and theoretical calculations.