Photoresponsive bilayer membranes composed of Ru(bpy)2+3 and methylviologen-containing layers sandwiched between ITO electrodes

Abstract A new sandwich type photoresponsive bilayer polymer device was fabricated which utilizes the photochemical reaction between Ru(bpy) 2+ 3 and methylviologen (MV 2+ ) confined in each Nafion layer. This photochemical diode, ITO/Nafion[Ru(bpy) 2+ 3 ]/Nafion[MV 2+ ]/ITO, generated (under air) a cathodic photocurrent with respect to the Ru complex-coated electrode. The action spectrum for the photocurrent showed that the photoexcitation of the Ru complex induced a photocurrent, indicating that electron transfer from the excited Ru complex to MV 2+ is the origin of the photoelectrochemical event. Higher membrane thickness induced higher photocurrent density within 1.6 μm of each layer. The photocurrent is discussed in relation to the partial mixing of the two reaction components in the membrane.