Tulio Matencio | UFMG - The Federal University of Minas Gerais (original) (raw)
Papers by Tulio Matencio
REM - International Engineering Journal, 2024
Electrochimica Acta, 1998
ABSTRACT
Eclética Química, Jan 22, 2018
DOAJ (DOAJ: Directory of Open Access Journals), 2006
The aim of this work is to present the theoretical and experimental aspects of the mirage effect ... more The aim of this work is to present the theoretical and experimental aspects of the mirage effect technique. We are especially interested in the concentration mirage effect, which is a powerful tool in the study of electrochemical reactions that produce ionic movements close to electrodes and to get some fundamental information on mass transport and charge transfer during electrochemical processes. Limitations of this technique are discussed as well as the recent attempts to overcome them.
Journal of Solid State Electrochemistry, 2016
Applied Surface Science, 2021
International Journal of Hydrogen Energy, 2020
Electrochimica Acta, 2020
Sustainable Aviation, 2022
Journal of Materials Science: Materials in Electronics, May 21, 2020
An easy and effective method for the preparation of a new impedimetric sensor used in the detecti... more An easy and effective method for the preparation of a new impedimetric sensor used in the detection of dimethyl sulfide (DMS) at a nanomolar level is presented. The sensor was prepared in two steps from a commercially available screen-printed carbon electrode (SPCE): a simple activation of the SCPE using cyclic voltammetry followed by electroless plating of the working electrode surface with gold clusters. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques confirmed the successful functionalization of the SPCE, revealing the presence of gold particles dispersed on the carbon matrix. Electrochemical impedance spectroscopy (EIS) was used to study the sensitivity of the sensor towards DMS dissolved in aqueous solution and simulated ocean water. Analyses were performed in less than 3 min, and the sensor showed linearity in a concentration range from 1.0 × 10 −10 to 1.0 × 10 −8 M with a limit of detection of 1.50 × 10 −9 M and a limit of quantification of 2.27 × 10 −9 M. To simulate the marine environment in which DMS is naturally present in nature, the impedance of the sensor was monitored by online EIS. Moreover, results indicated that, despite not linearly, the sensor is a promising tool to detect the analyte even at 1.0 × 10 −11 M, presenting an increase of resistance of 13.5% in relation to its bare condition.
Biomedical Journal of Scientific and Technical Research, May 21, 2019
Materials today communications, Dec 1, 2022
Biomedical Journal of Scientific & Technical Research, 2020
Journal of Biosensors & Bioelectronics, 2018
International Journal of Hydrogen Energy, 2018
Química Orgânica Sintética: Brasil 2022
Engenharias, ciência e tecnologia 3, 2019
Corrosion
Screen-printed carbon electrode (SPCE) was examined as a transducer substrate for application in ... more Screen-printed carbon electrode (SPCE) was examined as a transducer substrate for application in electrochemical sensors. Aqueous solutions of 0.1 M KCl and 0.1 M KCl + 5 mM K3[Fe(CN)6]/K4[Fe(CN)6] (redox solution) were prepared to simulate the environment of faradaic and non-faradaic sensing, respectively. The SPCE presented an irregular surface composed by two main carbon phases. Raman spectroscopy results revealed the presence of peaks around 1,580 cm−1 and 1,334 cm−1 related to the G and D bands corresponding to sp2 carbon atoms (graphite flakes) and a multitude of broad bands associable to amorphous sp3 carbon in the ink matrix. Conductive atomic force microscopy indicated that the irregular structure of the SPCE led to the heterogeneous distribution of the current over the surface and the electroactivity of this material was mainly attributed to the presence of graphite. Polarization curves and electrochemical impedance spectroscopy (EIS) revealed that the redox solution was m...
Journal of the Brazilian Chemical Society, 2022
In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and wit... more In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and with (LSMMO) mixed molybdenum oxides, were synthesized by the sol-gel route and deposited by immersion in carbon cloth substrates. Their performance as cathodes in the hydrogen peroxide reduction reaction (HPRR) and oxygen reduction reaction (ORR) was investigated through cyclic voltammetry and electrochemical impedance spectroscopy, the electrocatalytic efficiency of these electrodes in the HPRR was analyzed in KOH and H2O2 medium at 298 K. The performance of the cathodes, in a single compartment, using a nickel plate as an anode was also investigated. The results showed that for the reduction reactions, electrodes developed with LSMMO have more significant catalytic activity than LSM after polarization, resulting in 32% higher current densities, lower electrical resistance after polarization, and a 21% increase in power density.
Matéria (Rio de Janeiro), 2021
RESUMO Um dos desafios atuais é a busca de materiais eficientes e de baixo custo para os componen... more RESUMO Um dos desafios atuais é a busca de materiais eficientes e de baixo custo para os componentes das Pilhas a Combustível de Óxido Sólido (PaCOS), já que estes dispositivos se destacam pela geração limpa de energia elétrica e alta eficiência. Dentre estes componentes está o interconector, nos quais o aço inoxidável ferrítico poderia ser utilizado na sua fabricação. No entanto revestimentos protetores são necessários para bloquear a volatilidade do cromo da superfície metálica do interconector nas condições de operação das PaCOS. Neste trabalho, os revestimentos foram obtidos a partir de soluções eletrolítica contendo Co2+ e Mn2+ provenientes de catodos de baterias de íon lítio (BIL’s) exauridas. Foram feitas eletrodeposições potenciostáticas com o objetivo de se obter ligas de cobalto e manganês sobre a superfície de amostras do aço AISI 430. Dados de eficiência de carga do processo foram calculados para otimização das amostras, e a condição de pH mais ácido (pH=3) mostrou-se me...
REM - International Engineering Journal, 2024
Electrochimica Acta, 1998
ABSTRACT
Eclética Química, Jan 22, 2018
DOAJ (DOAJ: Directory of Open Access Journals), 2006
The aim of this work is to present the theoretical and experimental aspects of the mirage effect ... more The aim of this work is to present the theoretical and experimental aspects of the mirage effect technique. We are especially interested in the concentration mirage effect, which is a powerful tool in the study of electrochemical reactions that produce ionic movements close to electrodes and to get some fundamental information on mass transport and charge transfer during electrochemical processes. Limitations of this technique are discussed as well as the recent attempts to overcome them.
Journal of Solid State Electrochemistry, 2016
Applied Surface Science, 2021
International Journal of Hydrogen Energy, 2020
Electrochimica Acta, 2020
Sustainable Aviation, 2022
Journal of Materials Science: Materials in Electronics, May 21, 2020
An easy and effective method for the preparation of a new impedimetric sensor used in the detecti... more An easy and effective method for the preparation of a new impedimetric sensor used in the detection of dimethyl sulfide (DMS) at a nanomolar level is presented. The sensor was prepared in two steps from a commercially available screen-printed carbon electrode (SPCE): a simple activation of the SCPE using cyclic voltammetry followed by electroless plating of the working electrode surface with gold clusters. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques confirmed the successful functionalization of the SPCE, revealing the presence of gold particles dispersed on the carbon matrix. Electrochemical impedance spectroscopy (EIS) was used to study the sensitivity of the sensor towards DMS dissolved in aqueous solution and simulated ocean water. Analyses were performed in less than 3 min, and the sensor showed linearity in a concentration range from 1.0 × 10 −10 to 1.0 × 10 −8 M with a limit of detection of 1.50 × 10 −9 M and a limit of quantification of 2.27 × 10 −9 M. To simulate the marine environment in which DMS is naturally present in nature, the impedance of the sensor was monitored by online EIS. Moreover, results indicated that, despite not linearly, the sensor is a promising tool to detect the analyte even at 1.0 × 10 −11 M, presenting an increase of resistance of 13.5% in relation to its bare condition.
Biomedical Journal of Scientific and Technical Research, May 21, 2019
Materials today communications, Dec 1, 2022
Biomedical Journal of Scientific & Technical Research, 2020
Journal of Biosensors & Bioelectronics, 2018
International Journal of Hydrogen Energy, 2018
Química Orgânica Sintética: Brasil 2022
Engenharias, ciência e tecnologia 3, 2019
Corrosion
Screen-printed carbon electrode (SPCE) was examined as a transducer substrate for application in ... more Screen-printed carbon electrode (SPCE) was examined as a transducer substrate for application in electrochemical sensors. Aqueous solutions of 0.1 M KCl and 0.1 M KCl + 5 mM K3[Fe(CN)6]/K4[Fe(CN)6] (redox solution) were prepared to simulate the environment of faradaic and non-faradaic sensing, respectively. The SPCE presented an irregular surface composed by two main carbon phases. Raman spectroscopy results revealed the presence of peaks around 1,580 cm−1 and 1,334 cm−1 related to the G and D bands corresponding to sp2 carbon atoms (graphite flakes) and a multitude of broad bands associable to amorphous sp3 carbon in the ink matrix. Conductive atomic force microscopy indicated that the irregular structure of the SPCE led to the heterogeneous distribution of the current over the surface and the electroactivity of this material was mainly attributed to the presence of graphite. Polarization curves and electrochemical impedance spectroscopy (EIS) revealed that the redox solution was m...
Journal of the Brazilian Chemical Society, 2022
In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and wit... more In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and with (LSMMO) mixed molybdenum oxides, were synthesized by the sol-gel route and deposited by immersion in carbon cloth substrates. Their performance as cathodes in the hydrogen peroxide reduction reaction (HPRR) and oxygen reduction reaction (ORR) was investigated through cyclic voltammetry and electrochemical impedance spectroscopy, the electrocatalytic efficiency of these electrodes in the HPRR was analyzed in KOH and H2O2 medium at 298 K. The performance of the cathodes, in a single compartment, using a nickel plate as an anode was also investigated. The results showed that for the reduction reactions, electrodes developed with LSMMO have more significant catalytic activity than LSM after polarization, resulting in 32% higher current densities, lower electrical resistance after polarization, and a 21% increase in power density.
Matéria (Rio de Janeiro), 2021
RESUMO Um dos desafios atuais é a busca de materiais eficientes e de baixo custo para os componen... more RESUMO Um dos desafios atuais é a busca de materiais eficientes e de baixo custo para os componentes das Pilhas a Combustível de Óxido Sólido (PaCOS), já que estes dispositivos se destacam pela geração limpa de energia elétrica e alta eficiência. Dentre estes componentes está o interconector, nos quais o aço inoxidável ferrítico poderia ser utilizado na sua fabricação. No entanto revestimentos protetores são necessários para bloquear a volatilidade do cromo da superfície metálica do interconector nas condições de operação das PaCOS. Neste trabalho, os revestimentos foram obtidos a partir de soluções eletrolítica contendo Co2+ e Mn2+ provenientes de catodos de baterias de íon lítio (BIL’s) exauridas. Foram feitas eletrodeposições potenciostáticas com o objetivo de se obter ligas de cobalto e manganês sobre a superfície de amostras do aço AISI 430. Dados de eficiência de carga do processo foram calculados para otimização das amostras, e a condição de pH mais ácido (pH=3) mostrou-se me...