Edson Archela - Academia.edu (original) (raw)

Papers by Edson Archela

Semina: Ciências Exatas e Tecnológicas, 2013

Um dos principais constituintes presentes nos vinhos é a classe de compostos fenólicos, que compr... more Um dos principais constituintes presentes nos vinhos é a classe de compostos fenólicos, que compreende os ácidos fenólicos, flavonóides, lignanas e estilbenos. Estes influenciam nas principais características dos vinhos como sabor, aparência, fragrância, adstringência e nas propriedades antimicrobianas. São os responsáveis pela diferença entre os vinhos branco e tinto. Além disso, esta classe de composto tem sido muito estudada por suas propriedades antioxidantes que, acredita-se, ajudar na prevenção de doenças, como certos tipos de câncer, doenças cardiovasculares, diabetes, acidentes vasculares cerebrais e outras doenças relacionadas ao envelhecimento. Por isso, é de grande interesse o desenvolvimento de métodos para a determinação de compostos fenólicos que sejam sensíveis, seletivos, rápidos e de fácil operação. O presente trabalho traz uma revisão dos métodos que vem sendo empregados para a determinação de fenólicos até o presente ano.

Ionics, 2019

The present paper describes the use of electrodeposited Co(OH)2 on transparent conducting fluorin... more The present paper describes the use of electrodeposited Co(OH)2 on transparent conducting fluorine-doped tin oxide electrode (FTO) as functional material for ascorbic acid electrooxidation in different electrolyte solutions. The structure, composition, and morphology of film were investigated through Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectrum (EDS), and scanning electron microscope (SEM). The electrochemical characterization in different electrolyte solutions was carried out by cyclic voltammetry (CV) and chronoamperometry. The voltammetric profile showed the presence of two possible reactions involving almost reversible redox processes during sweeping potential in KOH solution and a single redox process in KCl solution. The Co(OH)2 film presented electrocatalytic activity in ascorbic acid electrooxidation, being the sensitivity values found were 182.3 mA L mol−1 cm−2 and 119.4 mA L mol−1 cm−2 in KOH and KCl solutions, respectively. The results showed that the electrolytic solution strongly influenced the sensitivity of the FTO/Co(OH)2 film in ascorbic acid electrooxidation reaction. Kinetic studies showed that the electrode process was controlled by mass diffusion. In addition, chronoamperometric technique was carried out to verify the stability of the electrode. The obtained results reveal a good stability of electrode in the KCl solution; once in current density terms, the results are quite similar.

International Journal of Electrochemical Science

In this work an easy way to prepared heterojunction electrodes based on ZnO and Cu2O were develop... more In this work an easy way to prepared heterojunction electrodes based on ZnO and Cu2O were developed. The electrodes were synthetized by a simple electrodeposition method. The photoelectrodes obtained were not submitted to a high temperature treatment. The electrodeposited films prevent the recombination of photogenerated charge carriers and thus allow the continuous formation of electrons and holes on photoelectrocatalytic reactions. Moreover, the films electrodeposited were characterized by X-ray diffraction, Raman spectroscopy, scanning electronic microscopy and UV-Vis. The photoelectrochemical activity was evaluated under visible light irradiation. The Cu2O addition at the photoelectrodes were efficient to improve the properties of pure ZnO and also promote superior photoelectrochemical and photoelectrocatalytic responses for methylene blue discoloration.

Semina: Ciências Exatas e Tecnológicas, 2013

Um dos principais constituintes presentes nos vinhos é a classe de compostos fenólicos, que compr... more Um dos principais constituintes presentes nos vinhos é a classe de compostos fenólicos, que compreende os ácidos fenólicos, flavonóides, lignanas e estilbenos. Estes influenciam nas principais características dos vinhos como sabor, aparência, fragrância, adstringência e nas propriedades antimicrobianas. São os responsáveis pela diferença entre os vinhos branco e tinto. Além disso, esta classe de composto tem sido muito estudada por suas propriedades antioxidantes que, acredita-se, ajudar na prevenção de doenças, como certos tipos de câncer, doenças cardiovasculares, diabetes, acidentes vasculares cerebrais e outras doenças relacionadas ao envelhecimento. Por isso, é de grande interesse o desenvolvimento de métodos para a determinação de compostos fenólicos que sejam sensíveis, seletivos, rápidos e de fácil operação. O presente trabalho traz uma revisão dos métodos que vem sendo empregados para a determinação de fenólicos até o presente ano.

Ionics, 2019

The present paper describes the use of electrodeposited Co(OH)2 on transparent conducting fluorin... more The present paper describes the use of electrodeposited Co(OH)2 on transparent conducting fluorine-doped tin oxide electrode (FTO) as functional material for ascorbic acid electrooxidation in different electrolyte solutions. The structure, composition, and morphology of film were investigated through Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectrum (EDS), and scanning electron microscope (SEM). The electrochemical characterization in different electrolyte solutions was carried out by cyclic voltammetry (CV) and chronoamperometry. The voltammetric profile showed the presence of two possible reactions involving almost reversible redox processes during sweeping potential in KOH solution and a single redox process in KCl solution. The Co(OH)2 film presented electrocatalytic activity in ascorbic acid electrooxidation, being the sensitivity values found were 182.3 mA L mol−1 cm−2 and 119.4 mA L mol−1 cm−2 in KOH and KCl solutions, respectively. The results showed that the electrolytic solution strongly influenced the sensitivity of the FTO/Co(OH)2 film in ascorbic acid electrooxidation reaction. Kinetic studies showed that the electrode process was controlled by mass diffusion. In addition, chronoamperometric technique was carried out to verify the stability of the electrode. The obtained results reveal a good stability of electrode in the KCl solution; once in current density terms, the results are quite similar.

International Journal of Electrochemical Science

In this work an easy way to prepared heterojunction electrodes based on ZnO and Cu2O were develop... more In this work an easy way to prepared heterojunction electrodes based on ZnO and Cu2O were developed. The electrodes were synthetized by a simple electrodeposition method. The photoelectrodes obtained were not submitted to a high temperature treatment. The electrodeposited films prevent the recombination of photogenerated charge carriers and thus allow the continuous formation of electrons and holes on photoelectrocatalytic reactions. Moreover, the films electrodeposited were characterized by X-ray diffraction, Raman spectroscopy, scanning electronic microscopy and UV-Vis. The photoelectrochemical activity was evaluated under visible light irradiation. The Cu2O addition at the photoelectrodes were efficient to improve the properties of pure ZnO and also promote superior photoelectrochemical and photoelectrocatalytic responses for methylene blue discoloration.