The Effect of Variation of Reactional Parameters in the Preparation of Graphene by Oxidation and Reduction of Graphite

Mehl, Hiany; Matos, Carolina Ferreira de; Neiva, Eduardo G.C.; Domingues, Sergio H.; Zarbin, Aldo J. G.

doi:10.5935/0100-4042.20140252

Cited by 32 publications

(47 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…17 The graphene species were obtained by a modified Hummers method, according to our previous work. 18 The surfactants sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (CTAB) were supplied by Sigma-Aldrich. H 2 SO 4 (Merck) and HNO 3 (Merck) analytical grade were used as received.…”

Section: Methodsmentioning

confidence: 99%

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

Matos¹,

Galembeck²,

Zarbin³

2016

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

This work describes the preparation, characterization and properties study of multifunctional nanocomposites between poly(styrene-co-butyl acrylate) latex and different carbon nanostructures: iron-filled carbon nanotubes (CNT), graphene or graphene oxide. Different approaches were employed to prepare stable aqueous dispersions of these nanostructures, according to the specificity of each nanomaterial. The nanocomposites were characterized by Raman and Fourier transform infrared (FTIR) spectroscopy, as well as by scanning probe microscopy (SPM) at different modes, providing information regarding the nature of the interaction between the carbon nanostructures and the polymeric matrix. The synergistic effect between the components results in improved mechanical, electrical, thermal and chemical properties of the nanocomposites, when compared to the neat polymer. In addition, the iron species into CNT cavities provide an interesting and unusual magnetic property of the nanocomposites. Results show that the properties of the nanocomposites can be modulated aiming desired application by simply selecting the amount and/or the kind of carbon nanostructure. This work provides information on the features of the three systems used, showing the range of properties that can be covered by using the three nano-fillers.

show abstract

Section: Methodsmentioning

confidence: 99%

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

Matos¹,

Galembeck²,

Zarbin³

2016

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Esta diferença, que também é observada nos nanocompósitos sintetizados (NC GOc/TiO 2 e NC GOs/TiO 2 ), provavelmente está associada a variações na rota de síntese do GO, o que costuma provocar diferenças na distribuição de grupos funcionais e defeitos. 16 As imagens obtidas por microscopia eletrônica de varredura confirmam as observações preliminares realizadas com base na DRX, mostrando diferenças significativas no tamanho de partícula apresentado pelo TiO 2 -P25 e pelas nanopartículas de TiO 2 sintetizadas neste trabalho (Figura 3). Embora os materiais tenham tendência a aglomerar, o que dificulta a visualização individual das partículas, observa-se que as nanopartículas sintetizadas (NPs TiO 2 ) apresentam um tamanho muito reduzido quando comparado ao fotocatalisador de referência (TiO 2 -P25), o que pode provocar diferenças no comportamento fotocatalítico destes materiais.…”

Section: Caracterização Dos Materiaisunclassified

“…O segundo evento, que vai até próximo a 300 o C está relacionado com a decomposição dos grupos funcionais oxigenados (hidroxilas, carbonilas e epoxilas) presentes nas folhas dos óxidos, enquanto que o terceiro evento (450 -600 o C) reflete a decomposição da estrutura do carbono. 16 Os termogramas obtidos para as nanopartículas de TiO 2 (NPs TiO 2 ) indicam uma perda de massa de aproximadamente 10% entre 25 e 135 o C, em razão da dessorção de água e de outros compostos adsorvidos na superfície das partículas.…”

Section: Caracterização Dos Materiaisunclassified

PHOTOCATALYTIC DEGRADATION OF DYE OVER GRAPHENE-TiO₂NANOCOMPOSITE

Nossol¹,

Rosa²,

Nossol³

et al. 2016

Química Nova

Self Cite

View full text Add to dashboard Cite

PHOTOCATALYTIC DEGRADATION OF DYE OVER GRAPHENE-TiO 2 NANOCOMPOSITE. In this work the sol-gel method was used to synthesize a nanocomposite containing TiO 2 and graphene oxide (GO). The photocatalytic activity of the TiO 2 /GO nanocomposite was evaluated regarding the degradation of a reactive dye (reactive black 5) in aqueous solution using processes assisted by UV-A radiation. Under these conditions the nanocomposite showed higher degradation efficiency than the reference photocatalyst (Degussa P25 TiO 2 ), mainly due to the high degradation capacity of the synthesized TiO 2 nanoparticles. Although contradictory to several reports in the specialized literature, no synergistic effect was observed between the nanocomposite components.Keywords: photocatalysis; nanocomposite; TiO 2 ; graphene oxide INTRODUÇÃODe maneira geral, grande parte do potencial poluente associado às atividades antrópicas está relacionado com a emissão de resíduos domésticos e industriais, os quais apresentam espécies químicas resistentes e tóxicas. Dentro do contexto industrial é possível destacar atividades de tingimento de fibras têxteis, 1 processo que é responsável pela geração de grandes volumes de resíduos contendo corantes não-fixados, alguns dos quais, mostrando resistência frente a rotinas convencionais de tratamento, contaminam o meio hídrico. 2Em função desta realidade, muitos esforços têm sido dedicados ao desenvolvimento de tecnologias alternativas, com claro destaque para os processos avançados de oxidação (POAs), 3 que permitem a degradação de substratos orgânicos de diversa natureza, eventualmente até completa mineralização.A degradação de corantes por POAs tem sido abundantemente relatada desde inícios da década de 1990, principalmente recorrendo-se a processos de fotocatálise heterogênea mediados por óxido de titânio.4 Para contornar alguns inconvenientes de ordem prática, principalmente representados pelas dificuldades encontradas na separação dos fotocatalisadores, usualmente em escala nanométrica, formas imobilizadas de TiO 2 tem sido propostas também desde a década de 1990, 5 utilizando-se suportes de diversa natureza.6 Particularmente interessante se mostra o uso de suportes constituídos por materiais carbonáceos, os quais, além de facilitar a separação e o reuso dos catalisadores, favorecem o processo de degradação, principalmente em função da sua elevada capacidade de adsorção facilitar a aproximação entre o radical hidroxila e as moléculas de poluente. Nos últimos anos numerosos trabalhos tem relatado um efeito sinérgico entre TiO 2 e grafeno, não apenas em função do efeito acima salientado, mas também em razão do favorecimento do processo de separação de cargas. No grafeno, a hibridização sp 2 dos átomos de carbono resulta em um orbital p vazio, que permite o transporte balístico dos elétrons fotogerados, o que, evitando o processo de recombinação do par e -/h + , favorece a geração de radical hidroxila e aumenta a capacidade de degradação do processo fotocatalítico. 8Em função desta constatação, muitos trabalhos ...

show abstract

“…The latter is particularly interesting since it is easily obtained in large amounts and comprises feasible functionalization sites. Indeed, GO, commonly obtained by the modified Hummer's method leads to several oxygenated groups on the surface. Upon reduction of GO, the conjugated network of graphene can be recovered, removing most of the oxygenated groups, giving reduced graphene oxide (rGO) .…”

Section: Introductionmentioning

confidence: 99%

Covalently linked nanocomposites of polypyrrole with graphene: Strategic design toward optimized properties

Naidek

Zarbin

Orth

2018

J. Polym. Sci. Part A: Polym. Chem.

Self Cite

View full text Add to dashboard Cite

Graphene-based nanocomposites with conducting polymers have attracted increasing interest due to the enhanced synergistic properties, which can potentiate and broaden applications. In this context, covalent functionalization stands out as a strategic designing tool, which optimizes the interaction between the nanocomposites components. Herein, covalently linked polymeric nanocomposites were obtained between graphene derivatives and polypyrrole (Ppy) under mild routes (i.e., aqueous, room temperature). First, pyrrole was covalently functionalized on graphene oxide (GO) through stable amide bonds and further polymerization with FeCl 3 led to the polymeric nanocomposites. Finally, to improve conductivity, GO was reduced using NaBH 4 . Similarly, analogous noncovalent nanocomposites were obtained for comparison purposes. All samples were thoroughly characterized by thermogravimetric analysis, scanning electron microscopy, and infrared and Raman spectroscopy, confirming the targeted functionalization, polymerization, and reduction processes. Moreover, the covalent link effectively enhances the interaction of the nanocomposite's components as evidenced by its improved electrochemical stability (300 cycles), compared to the non-covalent composites which loses conductivity in the initial stages. Indeed, Ppy is known for its low stability, limiting its applications. Overall, the results herein evidence that covalently linked nanocomposites can be successfully obtained with optimized electrochemical response, promising for applications as supercapacitors and artificial muscles.

show abstract

The Effect of Variation of Reactional Parameters in the Preparation of Graphene by Oxidation and Reduction of Graphite

Cited by 32 publications

References 0 publications

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

PHOTOCATALYTIC DEGRADATION OF DYE OVER GRAPHENE-TiO₂NANOCOMPOSITE

Covalently linked nanocomposites of polypyrrole with graphene: Strategic design toward optimized properties

Contact Info

Product

Resources

About

The Effect of Variation of Reactional Parameters in the Preparation of Graphene by Oxidation and Reduction of Graphite

Cited by 32 publications

References 0 publications

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

PHOTOCATALYTIC DEGRADATION OF DYE OVER GRAPHENE-TiO2NANOCOMPOSITE

Covalently linked nanocomposites of polypyrrole with graphene: Strategic design toward optimized properties

Contact Info

Product

Resources

About

PHOTOCATALYTIC DEGRADATION OF DYE OVER GRAPHENE-TiO₂NANOCOMPOSITE