Photoactivity of boron-or nitrogen-modified TiO2 for organic pollutants degradation: Unveiling the photocatalytic mechanisms and by-products

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Moreira, Ailton. J. ; dos Santos, Barbara R. M. ; Dias, Jeferson A. ; Rabello, Pietra T. ; Coelho, Dyovani ; Mascaro, Lucia H. ; Freschi, Gian P. G. ; Gobato, Yara G. ; Galeti, Helder V. A. ; Mastelaro, Valmor R. ; Pereira, Ernesto Chaves

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING; v. 11, n. 1, p. 12-pg., 2022-12-30.

Resumo

The degradation of fluoxetine (FLX) emerging pollutant and the formation of by-products, potentially present in environmental ecosystems, was investigated from photocatalytic processes. Applying different synthesis methods, nitrogen (TiN) or boron (TiB)-modified TiO2 presented oxygen vacancies (Vo & BULL;) responsible for generating intermediate energy levels, which acted as shallow traps to minimize the recombination processes and maintain the efficient separation of charge carriers. All photocatalysts showed the potential to produce hydroxyl radicals (& BULL;OH) from the oxidation of water in h+(VB), achieving 100% of RhB degradation under UV or visible irradiation. For the degradation of FLX, an alternative mechanism mediated by one of the by-products was confirmed after LC-MS-Q-TOF analysis. The protonation, dehalogenation and hydroxylation steps of FLX (m/z [H+] =310.1419) produce the transformation products TP8 (m/z[H+] = 310.1430), TP6 (m/z[H+] = 286.1454), and TP9 (m/z = 161.0221 (-ESI)), respectively. Other by-products have been identified after photodegradation, and their presence in FLX-contaminated ecosystems cannot be ignored. Therefore, high-performance photocatalysts obtained in this study are real alternatives for the environmental remediation of organic pollutants in aquatic ecosystems. (AU)

• Processo FAPESP: 17/11986-5 - Geração e Armazenamento de Novas Energias: trazendo desenvolvimento tecnológico para o país
• Beneficiário: Ana Flávia Nogueira
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 16/20609-8 - EMU concedido no projeto 2014/50249-8: cromatógrafo líquido de ultra-performance com CO2 supercrítico e detector de massas
• Beneficiário: Arlene Gonçalves Corrêa
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• 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