resumo
Herein, S-doped graphene flakes-based composites with Fe3O4 and/or CuS nanoparticles (NPs) are reported as photo-Fenton catalysts for the 4-nitrophenol (4-NP) degradation. The S-doped graphene flakes (S-GF) were prepared using a thermal treatment approach, and the nanocomposites by the in situ growth of Fe3O4 and/or CuS onto the S-GF scaffold. The characterization methods confirmed the formation of two- and three-components nanocomposites. The Fe3O4 NPs presented a cubic inverse spinel structure and the CuS phases a covellite structure, both with smaller crystallite sizes in the nanocomposites. The new nanocomposites showed higher ability to catalyze the photo-Fenton 4-NP degradation than the individual components. The S-GF@CuS-Fe3O4 nanocomposite exhibited the best catalytic activity: 95.2 % of 4-NP degradation, a kinetic of pseudo-first order (k=0.016 min(-1)), high photo-Fenton catalytic stability and catalyst's composition/structure preservation. The CuS NPs showed an important role in the photo-Fenton-like catalytic activity improvement.
palavras-chave
RAY PHOTOELECTRON-SPECTROSCOPY; ADVANCED OXIDATION PROCESSES; MICROWAVE-ASSISTED SYNTHESIS; SULFUR-DOPED GRAPHENE; FE3O4 NANOPARTICLES; PHOTOCATALYTIC DEGRADATION; ORGANIC POLLUTANTS; ELECTROCATALYTIC ACTIVITY; ELECTRO-FENTON; HETEROGENEOUS CATALYST
categoria
Chemistry, Inorganic & Nuclear
autores
Matos, R; Nunes, MS; Kuzniarska-Biernacka, I; Rocha, M; Guedes, A; Estrada, AC; Lopes, JL; Trindade, T; Freire, C
nossos autores
Ana Cristina Estrada
Investigador Júnior
Joana Lúcia Marto dos Santos Lopes
Estudante de doutoramento
Tito Trindade
Professor CatedráticoProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
agradecimentos
This work was financially supported by FundacAo para a Ciencia e a Tecnologia, I.P. (FCT) and EU under FEDER founds (POCI/01/0145/FEDER/007265), Programme PT2020 (UID/QUI/50006/2013) and projects FOTOCATGRAF (UT Austin|Portugal, Ref. UTAP-ICDT/CTM-NAN/0025/2014) and REWATER (Ref. WaterJPI/0007/2016). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials (UIDB/50011/2020 & UIDP/50011/2020), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. M. S. Nunes thanks her work contract in the frame of the project POCI-01-0145-FEDER-016422, funded by FCT/MCTES through national funds and FEDER (PT2020). I. Kuniarska-Biernacka and A. C. Estrada acknowledge the costs resulting from the FCT hirings funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. J. L. Lopes thanks FCT for her doctoral grant (SFRH/BD/126241/2016).