Photoelectric conversion from a nitrobenzene dye monolayer modified ITO electrode

Abstract

An amphiphilic nitrobenzene dye (C₁₈H₃₇)₂N–C₆H₄–CHN–NH–C₆H₄–NO₂ has been synthesized and deposited on semiconducting transparent indium–tin oxide (ITO) electrodes by a Langmuir–Blodgett (LB) technique. Photocurrent generation was studied in a conventional photoelectrochemical cell. An action spectrum of the photocurrent generation is coincident with the absorption spectrum of the LB film-modified electrode, indicating that the dye aggregate in the LB film is responsible for the photocurrent. Some factors which may affect the observed photocurrent, such as the presence of O₂, the concentration of methyl violet (MV²⁺), and hydroquinone (H₂Q), pH and the bias voltage have been investigated. Models for the mechanism of photocurrent generation under different conditions are proposed.