High catalytic activity of heteropolynuclear cyanide complexes containing cobalt and platinum ions: Visible-light driven water oxidation

Abstract

A near-stoichiometric amount of O<inf>2</inf> was evolved as observed in the visible-light irradiation of an aqueous buffer (pH 8) containing [RuII(2,2'-bipyridine)<inf>3</inf>] as a photosensitizer, Na<inf>2</inf>S<inf>2</inf>O<inf>8</inf> as a sacrificial electron acceptor, and a heteropolynuclear cyanide complex as a water-oxidation catalyst. The heteropolynuclear cyanide complexes exhibited higher catalytic activity than a polynuclear cyanide complex containing only CoIII or PtIV ions as C-bound metal ions. The origin of the synergistic effect between Co and Pt ions is discussed in relation to electronic and local atomic structures of the complexes. A platinum assist: A near-stoichiometric amount of O<inf>2</inf> was evolved as observed in the visible-light irradiation of an aqueous buffer (pH 8) containing [RuII(2,2'-bipyridine)<inf>3</inf>] as a photosensitizer, Na<inf>2</inf>S<inf>2</inf>O<inf>8</inf> as a sacrificial electron acceptor, and a heteropolynuclear cyanide complex as a water-oxidation catalyst. The synergistic effect between the Co and Pt ions was confirmed to facilitate the water-oxidation catalysis by the heteropolynuclear complex. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.