Synthesis and characterization of new NaX zeolite-supported Nb, Zn, and Fe photocatalysts activated by visible radiation for application in wastewater treatment

Brites-Nóbrega, Fernanda F.; Lacerda, Igor A.; Santos, Sara V.; Amorim, Camila C.; Santana, Veronice Slusarski; Fernandes-Machado, Nádia Regina Camargo; Ardisson, José D.; Henriques, Andréia Bicalho; Leão, Mônica Maria Diniz

doi:10.1016/j.cattod.2014.06.036

Cited by 13 publications

(6 citation statements)

References 38 publications

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“…Despite the low Si/Al ratio on zeolites NaA, they also have photocatalytic activity. That is because the hydrophilic surface favors the formation of hydroxyl radicals by the photoactivation and the hydrolysis of the surface adsorbed water (Brites-Nóbrega et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

<b>Synergistic effect between oxides semiconductors and zeolites on photobleaching of RB250 textile dye

et al. 2018

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The present work aims to evaluate the activity of semiconductor oxides (TiO 2 , Nb 2 O 5 and ZnO) supported on NaA and NaY zeolites, as well as their synergistic effect on Reactive Blue Dye (RB250) photodegradation process. Prior to deposition, TiO 2 particles size was reduced by ultrasonic scattering followed by filtration. The particles on the filtrate were used to conduct the experiments. The semiconductors were immobilized in concentrations of 2.5, 5 and 10% (w w -1 ) and the photocatalytic tests were performed at catalyst concentrations of 1 and 2 g L -1 . Moreover, supported catalysts were characterized by XRD, textural analysis, zero point of charge and temperature programmed desorption of NH 3 . A comparison between the supported catalysts showed high activity for the ones supported with ZnO and TiO 2 . Zeolite NaY has broader opened channels than NaA, which reduces the dye molecules blockage, and, as a result, increased the catalyst activity. A higher concentration of supported catalysts (2 g L -1 ) provides greater photocatalytic activity, while higher concentration of semiconductors immobilized on supports does not present significant differences.Efeito sinérgico entre óxidos semicondutores e zeólitas no fotoclareamento do corante têxtil RB250 RESUMO. O objetivo deste trabalho foi avaliar a atividade dos óxidos semicondutores (TiO 2 , Nb 2 O 5 & ZnO) suportados nas zeólitas NaA e NaY e seu efeito sinérgico na fotodegradação do corante têxtil azul reativo (RB250). Antes da deposição, o tamanho das partículas de TiO 2 foi reduzido por dispersão em ultrassom seguido por filtração e foram utilizadas as partículas que passaram através do filtro. Os semicondutores foram imobilizados em concentrações de 2,5, 5 e 10% (m m -1 ) e os testes fotocatalíticos foram realizados em concentrações de catalisador de 1 e 2 g L -1 . Os catalisadores suportados foram caracterizados por DRX, análise textural, ponto de carga zero e dessorção por temperatura programada. Os catalisadores suportados com ZnO e TiO 2 mostraram maior atividade do que o Nb 2 O 5 . Os testes fotocatalíticos indicaram um aumento na atividade dos catalisadores suportados em NaY sendo essa com resultados superiores aos encontrados com a zeólita NaA. Isso por causa dos seus canais mais estreitos que dificultam a entrada de moléculas do corante. A maior concentração de catalisadores suportados (2 g L -1 ) proporciona maior atividade fotocatalítica, enquanto a maior concentração de semicondutores imobilizados em suportes não apresenta diferenças significativas.

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Section: Introductionmentioning

confidence: 99%

<b>Synergistic effect between oxides semiconductors and zeolites on photobleaching of RB250 textile dye

et al. 2018

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“…Fe acted as an abrasive (Figure b). This result may indicate that the iron ion did not adsorb in the zeolite matrix, but formed instead an “egg‐shell” structure on the surface . On the other hand, a smooth surface is observed for Cu/NaX zeolite (Figure c).…”

Section: Resultsmentioning

confidence: 92%

Eco‐friendly synthesis from industrial wastewater of Fe and Cu nanoparticles over NaX zeolite and activity in 4‐nitrophenol reduction

et al. 2018

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We deposited Fe and Cu over zeolite NaX (Fe/NaX and Cu/NaX) by adsorption from effluent industrial wastewater. We synthesized the zeolite NaX by the hydrothermal method. 5 g of NaX completely adsorbed 350 and 380 mg of Fe and Cu from the industrial wastewater, respectively, in 6 h. The distribution of Fe and Cu over the NaX was uniform and amounted at 14 and 18 mass%, respectively. Fe and Cu modify the morphology of the NaX zeolite: the particle size increased from 9 μm to 10 μm for the former and decreased to 3 μm for the latter. Fe/NaX and Cu/NaX are less crystalline than NaX. BET analysis showed that the specific surface area decreased by 30 % and 50 % compared to NaX for Fe/NaX and Cu/NaX, but the ratio between meso‐ and micropores increased by 7 and 13 times, respectively. Fe/NaX and Cu/NaX synthesized by adsorption from industrial wastewater reduced +99 % of 4‐p‐nitrophenol to 4‐aminophenol in less than 100 s, which is comparable to noble metal.

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“…The band gap energy on Table 4 for zeolite ZSM-5 does not necessarily indicate the value of the excitation energy of the valence band electrons. Zeolites are not semiconductors, so the calculated energy is ISSN: 2525-8761 related to excitation of aluminum atoms in the zeolite structure [29]. The reduction of the band gap energy along with the deposition of TiO2 is due to the synergic effect between the zeolite and the titanium.…”

Section: Resultsmentioning

confidence: 99%

Mechanochemical Synthesis of Anatase-Rutile Phases at Ball Milling in Different Conditions and Its Cause and Effect on a Photo-Oxidation Process / Síntese Mecano-Química De Fases Anatômicas Na Moagem De Bolas Em Diferentes Condições E Sua Causa E Efeito Em Um Processo De Foto-Oxidação

Vicentini

Subtil

Oliveira

et al. 2021

BJD

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This study aims to evaluate the effect of the grinding parameters applied to TiO2 comminution, which forms a heterojunction of anatase-rutile phases and reduces markedly the size particle. This material is a well-knowm photocatalyst in environmental issues such as degradation of synthetic dyes, mainly due to the large surface area and oxidative radicals generations ability. The influence of time, rotational speed and the solvent was investigated in the grinding process. Catalysts were prepared by a deposition method and were characterized by XRD, textural analysis (BET area), potential electrophoretic, photoacoustic and Mössbauer spectroscopy. The comminution procedure reduced the size of TiO2 crystallites from 87 nm to 22 nm as well as the surface area and pore diameter. The best photocatalytic activity was for TiO2 comminuted for 10 min and 300 rpm in a dry medium supported on ZSM-5. It was registered that the photoactivity of TiO2 decreased with the transition of anatase to rutile phase and also by the iron oxides insertion during the comminution process. This study has a great technologic contribution because it elucidates primary issues on the particle sizes reduction in the catalysts production, whose function is to have a better metal distribution on the support's surface.

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Synthesis and characterization of new NaX zeolite-supported Nb, Zn, and Fe photocatalysts activated by visible radiation for application in wastewater treatment

Cited by 13 publications

References 38 publications

<b>Synergistic effect between oxides semiconductors and zeolites on photobleaching of RB250 textile dye

<b>Synergistic effect between oxides semiconductors and zeolites on photobleaching of RB250 textile dye

Eco‐friendly synthesis from industrial wastewater of Fe and Cu nanoparticles over NaX zeolite and activity in 4‐nitrophenol reduction

Mechanochemical Synthesis of Anatase-Rutile Phases at Ball Milling in Different Conditions and Its Cause and Effect on a Photo-Oxidation Process / Síntese Mecano-Química De Fases Anatômicas Na Moagem De Bolas Em Diferentes Condições E Sua Causa E Efeito Em Um Processo De Foto-Oxidação

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