title: Homogeneous and Heterogeneous Photocatalytic Water Oxidation by Persulfate.
abstract: Photocatalytic water oxidation by persulfate (Na2 S2 O8 ) with [Ru(bpy)3 ](2+) (bpy=2,2'-bipyridine) as a photocatalyst provides a standard protocol to study the catalytic reactivity of water oxidation catalysts. The yield of evolved oxygen per persulfate is regarded as a good index for the catalytic reactivity because the oxidation of bpy of [Ru(bpy)3 ](2+) and organic ligands of catalysts competes with the catalytic water oxidation. A variety of metal complexes act as catalysts in the photocatalytic water oxidation by persulfate with [Ru(bpy)3 ](2+) as a photocatalyst. Herein, the catalytic mechanisms are discussed for homogeneous water oxidation catalysis. Some metal complexes are converted to metal oxide or hydroxide nanoparticles during the photocatalytic water oxidation by persulfate, acting as precursors for the actual catalysts. The catalytic reactivity of various metal oxides is compared based on the yield of evolved oxygen and turnover frequency. A heteropolynuclear cyanide complex is the best catalyst reported so far for the photocatalytic water oxidation by persulfate and [Ru(bpy)3 ](2+) , affording 100 % yield of O2 per persulfate.
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea. fukuzumi@chem.eng.osaka-u.ac.jp.|Faculty of Science and Engineering, Meijo University, ALCA and SENTAN, Japan Science and Technology Agency (JST), Nagoya, Aichi, 468-0073, Japan. fukuzumi@chem.eng.osaka-u.ac.jp.|Graduate School of Engineering, Osaka University, ALCA and SENTAN, Japan Science and Technology Agency (JST), Suita, Osaka, 565-0871, Japan. fukuzumi@chem.eng.osaka-u.ac.jp.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan. ymd@a-chem.eng.osaka-cu.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Chemistry, Faculty of Pure and Applied Science, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan. kojima@chem.tsukuba.ac.jp.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Kojima
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea. wwnam@ewha.ac.kr.
authors.forename: Wonwoo
authors.initials: W
authors.lastname: Nam
keywords: heterogeneous catalysis; homogeneous catalysis; nanoparticles; photocatalysis; water oxidation