| Texto completo | |
| Autor(es): |
de Araujo, Moises A.
;
Gromboni, Murilo F.
;
Marken, Frank
;
Parker, Stephen C.
;
Peter, Laurence M.
;
Turner, Josh
;
Aspinall, Helen C.
;
Black, Kate
;
Mascaro, Lucia H.
Número total de Autores: 9
|
| Tipo de documento: | Artigo Científico |
| Fonte: | APPLIED CATALYSIS B-ENVIRONMENTAL; v. 237, p. 14-pg., 2018-12-05. |
| Resumo | |
Photo-catalytic performance for oxide films, here for inkjet-printed TiO2 (ca. 1 mu m thickness on PTO) and for spray-pyrolysis-coated Nb2O5 (ca. 1 mu m thickness on PTO), is affected by oxygen vacancies that form during vacuum-heat treatment at 550 degrees C. The effects of the oxygen vacancies are associated with formation of Ti(III) and Nb(IV) sites, respectively, and therefore optically visible as "grey" coloration. Photo-electrochemical light-on-off transient experiments are performed in the limit of thin film photoanodes, where front and back illumination result in the same photo-current responses (Le. with negligible effects from internal light absorption gradients). It is shown that generally the magnitude of photo-currents correlates linearly with light intensity, which is indicative of dominant "photo-capacitive" behaviour. At an applied voltage of 0.4 V vs. SCE (in the plateau region of the photo-current responses) the potential and also the pH (going from 1.0 M KOH to 0.1 M HClO4 in the presence of methanol quencher) have no significant effect on photo-currents; that is, surface chemical/kinetic effects appear to be unimportant and interfacial hole transfer may be rate limiting. Under these conditions (and based on a simplistic mechanistic model) changes in photo-currents introduced by oxygen vacancy doping (detrimental for TiO2 and beneficial for Nb2O5) are assigned primarily to changes in electron mobility. (AU) | |
| Processo FAPESP: | 16/12681-0 - Obtenção e caracterização de filmes finos do semicondutor ternário sulfeto de antimônio e estanho, TAS (T=estanho,A=antimônio e S=enxofre), para aplicação em células fotovoltaicas |
| Beneficiário: | Moisés Albuquerque de Araújo |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 14/50249-8 - Green chemistry: sustainable synthetic methods employing benign solvents, safer reagents, and bio-renewable feedstock |
| Beneficiário: | Arlene Gonçalves Corrêa |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa Centros de Pesquisa Aplicada |
| Processo FAPESP: | 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais |
| Beneficiário: | Elson Longo da Silva |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |