Visible light photoelectrochemical activity of K4Nb6O17 intercalated with photoactive complexes by electrostatic self-assembly deposition

Electrostatic self-assembly deposition (ESD) results in the intercalation of Ru(bpy)2/3(+) or methylene blue (MB) into the niobate layered oxide right after the cations come into contact with [Nb6O17](4-) nanosheets. Monolayers can be obtained by the exfoliation of proton exchanged K4Nb6O17 (KNbO) in an aqueous tetrabutylammonium (TBA) solution as revealed by the atomic force microscopy micrographs. UV-vis spectra show that intercalated films are able to absorb in the visible light range. Heat-treatment of Ru(bpy)2/3(+) resulted in the red-shift in the absorption spectra, which was assigned to the enhancement in the interaction between the complex molecules and [Nb6O17](4-) host layer. Intercalated niobate layered oxides are able to produce photocurrent as a result of the electron transfer from the excited guest molecule to the host layer under visible light illumination. Ru(bpy)2/3(+) intercalated niobate layered oxide shows photocatalytic activity under visible light illumination to produce H-2 from water-methanol solution. (c) 2005 Elsevier Inc. All rights reserved.