Graphite–castor oil polyurethane composite electrode surfaces – AFM morphological and electrochemical characterisation

• Autor(a) principal: Paquim, Ana Maria Chiorcea
• Data de Publicação: 2014
• Outros Autores: Diculescu, Victor Constantin, Cervini, Priscila, Cavalheiro, Eder Tadeu Gomes, Brett, Ana Maria Oliveira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/27823; https://doi.org/10.1016/j.jelechem.2014.07.027
• topic: Graphite; Polyurethane; Composite electrode material; AFM; Voltammetry

Graphite–castor oil polyurethane composite electrodes with different graphite weight percentages, 30–70% graphite–polyurethane w w−1, were morphologically studied by atomic force microscopy (AFM) and voltammetry. AFM images and r.m.s. roughness measurements demonstrated that the polyurethane roughness decreased with increasing the graphite content, composites of 50% and 60% graphite–polyurethane w w−1 showing the smother electrode surface. The electrochemical characterisation was performed in solutions of K4Fe(CN)6 by cyclic voltammetry and impedance spectroscopy. For compositions of 60% and 70% graphite–polyurethane w w−1, the cyclic voltammetry results showed the K4Fe(CN)6 system reversibility. The charge transfer resistance, determined from the EIS spectra, decreased significantly with increasing the graphite/polyurethane ratio, and the capacitance increased for higher graphite percentages. AFM and voltammetric results enable to conclude that 60% graphite–polyurethane w w−1 was the optimal composition for the preparation of the graphite–polyurethane composite electrodes.