Fabrication of high surface area graphene electrodes with high performance towards enzymatic oxygen reduction

High surface area graphene electrodes were prepared by simultaneous electrodeposition and electroreduction of graphene oxide. The electrodeposition process was optimized in terms of pH and conductivity of the solution and the obtained graphene electrodes were characterized by X-ray photoelectron spe...

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Detalles Bibliográficos
Autores: Di Bari, Chiara, Goñi-Urtiaga, Asier, Pita, Marcos, Shleev, Sergey, Toscano, Miguel D., Sainz, Raquel, López de Lacey, Antonio
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/142696
Acceso en línea:http://hdl.handle.net/10261/142696
Access Level:acceso abierto
Palabra clave:Biocathode
Oxygen Reduction Reaction
Graphene
Bilirubin oxidase
Laccase
Descripción
Sumario:High surface area graphene electrodes were prepared by simultaneous electrodeposition and electroreduction of graphene oxide. The electrodeposition process was optimized in terms of pH and conductivity of the solution and the obtained graphene electrodes were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy and electrochemical methods (cyclic voltammetry and impedance spectroscopy). Electrodeposited electrodes were further functionalized to carry out covalent immobilization of two oxygen-reducing multicopper oxidases: laccase and bilirubin oxidase. The enzymatic electrodes were tested as direct electron transfer based biocathodes and catalytic currents as high as 1 mA/cm2 were obtained. Finally, the mechanism of the enzymatic oxygen reduction reaction was studied for both enzymes calculating the Tafel slopes and transfer coefficients.