title: Layer-by-layer self-assembly polytungstogermanate multilayer films and their photocatalytic properties under sunlight irradiation.
abstract: The dilacunary decatungstogermanate [γ-GeW(10)O(36)](8-) (GeW(10)) and the monolacunary undecatungstogermanate [β(2)-GeW(11)O(39)](8-) (GeW(11)) were employed as polyanions to layer-by-layer self-assembly with cationic thionine (TH) dye. The (GeW(10)/TH)(n) and (GeW(11)/TH)(n) composite films were characterized by UV-vis spectra, atomic force microscopy images (AFMs) and cyclic voltammograms (CV). Their photocatalytic activities were evaluated by photocatalytic degradation of methyl orange aqueous solution under sunlight irradiation. The results indicated that the (GeW(10)/TH)(n) and (GeW(11)/TH)(n) films exhibited the sunlight photocatalytic activities for methyl orange (MO) solution. The dye molecule TH extended the light absorption spectrum of polyoxometalates toward the visible light region. The photocatalytic mechanism of composite films was also discussed.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou 350002, China.
authors.forename: Shuiying
authors.initials: S
authors.lastname: Gao
authors.forename: Danmei
authors.initials: D
authors.lastname: Pan
authors.forename: Rong
authors.initials: R
authors.lastname: Cao
mesh_terms: D001391:Azo Compounds; D002384:Catalysis; D004396:Coloring Agents / Q000528:radiation effects*; D005857:Germanium; D010640:Phenothiazines; D055668:Photochemical Processes; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry* / Q000528:radiation effects; D013472:Sunlight; D014414:Tungsten; D017973:Tungsten Compounds; D000099294:Polyoxometalates
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D005857:Germanium; D010640:Phenothiazines; D000071228:Polyelectrolytes; D011108:Polymers; D014414:Tungsten; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates; C100258:methyl orange; C009469:thionine