| Texto completo | |
| Autor(es): |
Gusmao, Carolina de Araujo
;
Palharim, Priscila Hasse
;
Ramos, Bruno
;
Gouvea, Douglas
;
Rodrigues Jr, Orlando
;
Teixeira, Antonio Carlos Silva Costa
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Materials Science; v. 59, n. 4, p. 20-pg., 2024-01-01. |
| Resumo | |
Ag-TiO2/SiO2 materials were synthesized with 1, 3, 5, and 10 wt% Ag contents and extensively characterized by different techniques, including XRD, SEM, TEM, XPS, BET, UV-VIS, EPR, and PL spectroscopy. Subsequently, the activity of these materials in the degradation of a model volatile organic compound (n-hexane) was compared by testing in a continuous gas-solid photoreactor. Loading with Ag induced stabilization of the brookite phase and crystal growth. TEM images showed d-spacing values corresponding to anatase and metallic silver. The specific surface area was lower in the Ag-modified catalysts, probably due to the blocking of the silica gel pores by Ag nanoparticles, whose size (similar to 20 nm) was larger than the silica pores (similar to 1.98 nm). SEM-EDS images showed heterogeneous distribution of Ag on the surface of the materials. XPS spectra showed bands referring to Ag+ and Ag-0 3d, and Ti4+ and Ti3+ 2p. EPR analyses showed that silver loading of TiO2/SiO2 greatly increased the occurrence of oxygen vacancies in the material. Finally, the band gap energies calculated from the UV-VIS spectra were lower in the silver-containing catalysts, dropping from 3.25 to 3.17 eV in the optimal material. Under visible light, while TiO2/SiO2 showed no photoactivity, the Ag-modified materials presented satisfactory steady-state performance (46.4% n-hexane removal). [Graphics] . (AU) | |
| Processo FAPESP: | 19/24158-9 - Destinação ambiental de poluentes emergentes em águas superficiais e alternativas sustentáveis de mitigação: abordagem híbrida experimental-computacional |
| Beneficiário: | Antonio Carlos Silva Costa Teixeira |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |