Dye photodegradation employing mesoporous organosilicas functionalized with 1,8-naphthalimides as heterogeneous catalysts

Author(s)

Castanheira, Bruna ; Trindade, Fabiane de Jesus ; Andrade, Luana dos Santos ; Nantes, Iseli Lourenco ; Politi, Mario Jose ; Triboni, Eduardo Rezende ; Brochsztain, Sergio

• Document type: Journal article
• Source: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY; v. 332, p. 316-325, JAN 1 2017.
• Web of Science Citations: 2

Abstract

Mesoporous organosilicas containing covalently bound 1,8-naphthalimides (NI) were shown to be efficient heterogeneous catalysts for the photodegradation of methylene blue (MB), a typical textile pollutant. The NI-containing mesoporous silicas (SBANI materials) were prepared by a co-condensation reaction, in conditions similar to those used for inorganic SBA-15. For the photocatalytic tests, the SBANI materials were suspended in aqueous MB solutions, and the suspensions were irradiated with a 100 W Hg lamp (bandpass filter: 320-480 nm). The activity of the SBANI catalysts was proportional to the NI content in the sample. When MB was irradiated in the presence of a sample with high NI content, total bleaching of MB was observed after 300 min irradiation. In addition, blue shifts in the visible MB band were observed during irradiation. The results can be explained by concomitant mineralization and Ndemethylation of MB. N-demethylation led to the formation of azure dyes, which were detected in the reaction mixtures after irradiation. The photocatalytic activity can be attributed to the formation of NI triplets, which can react with MB by both Type (II) (via oxygen reactive species) and Type I (via electron transfer) mechanisms. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 15/06064-6 - Functional organic molecules and inorganic oxides for the development of new materials
• Grantee: Eduardo Rezende Triboni
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/07456-7 - Flow cytometry studies of cell death and protection promoted by porphyrinoid compounds, phenothiazines and Teluranes associated to nanostructures in a cell biology multiuser lab
• Grantee: Iseli Lourenço Nantes Cardoso
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/16358-9 - Synthesis and characterization of functional materials containing aromatic imides
• Grantee: Sergio Brochsztain
• Support Opportunities: Regular Research Grants
• FAPESP's process: 07/08720-1 - Preparation of nanostructured mesoporous materials modified with aromatic imides for applications in photonics and electronics
• Grantee: Fabiane de Jesus Trindade
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 08/04948-0 - Structure and reactivity of hemepeptides, hemeproteins and phorphyrins in homogeneous and heterogenoeus media: basic aspects and application in nanotechnology
• Grantee: Iseli Lourenço Nantes Cardoso
• Support Opportunities: Research Projects - Thematic Grants