Autor(es)

Escanio, Camila A. ; dos Santos, Suelem ; Natale, Julia M. ; Almeida, Dalva ; Trava-Airoldi, Vladimir J. ; Corat, Evaldo J.

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 128, n. 13, p. 15-pg., 2024-03-21.

Resumo

This work developed a composite of the conducting polymer polyaniline (PAni) with lead that has a high onset potential for hydrogen evolution in a high-concentration acid solution. The aim was to avoid hydrogen evolution from a carbon fiber current collector, considering its application in lead-acid batteries. In a 5 M H2SO4 solution, the onset potential was as high as -0.75 V vs Ag/AgCl. The study revealed that the Pb2+ ions strongly interact with the nitrogen present in the PAni structure. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy gave an insight into how the interaction between lead ions and the nitrogen takes place, which is described schematically. This composite is stable and keeps the high onset potential, while Pb2+ is associated with nitrogen, as evaluated in various potentials through chronoamperometry and cyclic voltammetry conditions. The Pb2+ desorbs for potentials higher than -0.65 V vs Ag/AgCl and degrades the composite onset potential. The desorption was reversible as long as the PbSO4 particles formed were nanometric and immersed in the PAni. Desorption for long periods forms large PbSO4 particles; consequently, the reduction of these particles becomes difficult. Without Pb2+ ions, it is not possible to restore the interaction between Pb2+ and PAni. Besides XPS and Raman spectroscopy, the material characterization was performed by field emission gun scanning electron microscopy and energy-dispersive X-ray spectroscopy. The electrochemical characterization involved cyclic voltammetry, linear sweep voltammetry, galvanostatic charge-discharge cycles, and chronoamperometry. (AU)

• Processo FAPESP: 19/08473-1 - Desenvolvimento de supercapacitores de nanotubos de carbono para aplicações em baterias de chumbo-ácido
• Beneficiário: Camila Alves Escanio
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 22/12018-0 - Produção de papel (tipo buckypaper) de nanotubos de carbono intermeados por carvão ativado
• Beneficiário: Julia Marchesi Natale
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 22/07225-7 - Estudo de supercapacitores EDLC para aplicações em deionização capacitiva
• Beneficiário: Suelem Soares dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 19/18572-7 - Novos materiais de carbono: suas aplicações espaciais, ambientais e spin offs relevantes
• Beneficiário: Evaldo Jose Corat
• Modalidade de apoio: Auxílio à Pesquisa - Temático