Surface structure and reactivity study of phosphotungstic acid-nitrogenated ormosils

Autor(es)

Ferreira-Neto, Elias P. ^[1] ; de Carvalho, Flavio L. S. ^[1] ; Ullah, Sajjad ^[1] ; Zoldan, Vinicius C. ^[2] ; Pasa, Andre A. ^[2] ; de Souza, Adriano Lopes ^[1] ; Battirola, Liliane C. ^{[1, 3]} ; Rudolf, Petra ^[3] ; Aldabe Bilmes, Sara ^[4] ; Rodrigues-Filho, Ubirajara P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Fed Santa Catarina, Lab Filmes Finos & Superficies, Dept Fis, BR-88040900 Florianopolis, SC - Brazil

^[3] Univ Groningen, Zernike Inst Adv Mat, NL-9747 AG Groningen - Netherlands

^[4] Univ Buenos Aires, Fac Ciencias Exactas & Nat, Inst Quim Fis Mat, Medio Ambiente & Energia INQUIMAE, Buenos Aires, DF - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Journal of Sol-Gel Science and Technology; v. 66, n. 3, p. 363-371, JUN 2013.
• Citações Web of Science: 9

Resumo

Supramolecular interactions between nitrogenated groups in hybrid ormosils bearing phosphotungstate nanocatalyst were used to tune the photocatalytical activity of these class-II hybrid materials obtained through sol-gel chemistry. Surface chemistry and morphology of the materials was studied by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and water contact angle measurements. The photocatalytic efficiency of these hybrid films, measured by the degradation of crystal violet over-layer deposited on ormosils films, is higher for ormosils bearing neutral, more polar and less H-bonding nitrile groups than those bearing alkylamine/alkylammonium functionalities, despite the lower W/Si atomic ratio on the surface and lower tungsten percentage of the pure nitrile bearing ormosils. Such higher surface reactivity of the nitrile bearing ormosils is due to weaker interaction with the phosphotungstate and the lower activity of amine bearing ormosils is attributed to the competition among reversible photochromism and photocatalysis pathways in these materials. (AU)

• Processo FAPESP: 11/08120-0 - Filmes nanoestruturados: impacto da arquitetura dos filmes contendo nanopartículas e fosfotungstato sobre as propriedades fotoativas
• Beneficiário: Ubirajara Pereira Rodrigues Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular