Photocatalytic water cleavage using a mixture of ruthenium tris-bipyridyl chloride and zinc phthalocyanine as photosensitizers

Abstract

Photoinduced electron transfer and hydrogen evolution from water were investigated, using each of the two photocatalysts ruthenium tris-bipyridyl complex [Ru(bip) 2+ 3], zinc phthalocyanine and their mixture, with methyl viologen (MV 2+) as an electron acceptor, ethylene diamine tetraacetic acid as electron donor and colloidal platinum in polyvinyl alcohol (Pt-PVA) as hydrogen redox catalyst, in cetyl trimethyl ammonium bromide (CTAB) (10 −2 M) at pH 6.5. The efficiency of methyl viologen reduction by zinc phthalocyanine increased on addition of [Ru(bip) 2+ 3] complex, using visible light (350–700 nm) from a xenon arc lamp. Optimum concentrations of colloidal platinum in the presence of each of the two metal complexes and their mixtures were also studied. Evolution of hydrogen took place using the two photosensitizers in absence of methyl viologen.