Supercapacitive properties, anomalous diffusion, and porous behavior of nanostructured mixed metal oxides containing Sn, Ru, and Ir
José J.S. Teles, Emanuel R. Faria, Jéferson H. M. Santos, Lindomar G. De Sousa, Débora V. Franco, Willian G. Nunes, Hudson Zanin, Leonardo M. Da Silva
ARTIGO
Inglês
Agradecimentos: L.M. Da Silva wishes to thank the "Fundação ao Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG" (Project APQ-02739-17), "Secretaria de Estado de Ciência, Tecnologia e Ensino Superior de Minas Gerais, SECTES/MG" (Support for the LMMA Laboratory), and "Conselho Nacional de...
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Agradecimentos: L.M. Da Silva wishes to thank the "Fundação ao Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG" (Project APQ-02739-17), "Secretaria de Estado de Ciência, Tecnologia e Ensino Superior de Minas Gerais, SECTES/MG" (Support for the LMMA Laboratory), and "Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq" (PQ-2 grant). H. Zanin wishes to thank the financial support from the Brazilian funding agencies CNPq (301486/2016-6) and FAPESP (2014/02163-7 & 2017/11958-1)
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Different nanostructured mixed metal oxide (MMOs) electrodes containing Sn, Ru, and Ir supported on titanium with the nominal composition Ti/[Sn0.5Ru(0.5−x)Ir(x)]O2 were prepared using the drop-coating method. SEM analysis revealed the presence of oxide islands in the microsized domains of ca. 50 μm...
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Different nanostructured mixed metal oxide (MMOs) electrodes containing Sn, Ru, and Ir supported on titanium with the nominal composition Ti/[Sn0.5Ru(0.5−x)Ir(x)]O2 were prepared using the drop-coating method. SEM analysis revealed the presence of oxide islands in the microsized domains of ca. 50 μm separated from each other by cracks. On the contrary, analysis of the nanosized domains revealed the presence of nanostructures containing rectangular grains with an average diameter of ca. 200 nm. The discrepancy between the nominal and real oxide compositions was attributed to volatilizationof Sn during the heat treatment. XRD analysis revealed a poor degree of crystallinity and an average crystallite size of 15 ± 4 nm. Different electrochemical studies revealed higher specific pseudocapacitances in the range of 175–222 F g−1for the MMO containing 50 mol% Ir. The low values obtained for the morphology factor (0.11 ≤ φ ≤ 0.33) indicate a relatively narrow interval of 11–33% for the active surface regions confined to the inner surface regions of the oxide layers. The chronoamperometric findings obtained for short times (t ≤ 50 ms) permitted evaluation of the electrical double-layer capacitance (Cedl), with verified maximum values in the range of 68–75 F g−1 for the MMO containing 50 mol% Ir. On the contrary, the experimental findings obtained for long times (0.1 s ≤ t ≤ 3 s) revealed that the reversible solid-state Faradaic reactions did not exhibit a Fickian behavior. The impedance analysis revealed that MMOs exhibit a porous electrode behavior (De Levie’s model) permitting the determination of the pseudocapacitance and the resistance of the electrolyte inside the pores.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
301486/2016-6
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIG
APQ-0273917
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
2014/02163-7; 2017/11958-1
Fechado
Supercapacitive properties, anomalous diffusion, and porous behavior of nanostructured mixed metal oxides containing Sn, Ru, and Ir
José J.S. Teles, Emanuel R. Faria, Jéferson H. M. Santos, Lindomar G. De Sousa, Débora V. Franco, Willian G. Nunes, Hudson Zanin, Leonardo M. Da Silva
Supercapacitive properties, anomalous diffusion, and porous behavior of nanostructured mixed metal oxides containing Sn, Ru, and Ir
José J.S. Teles, Emanuel R. Faria, Jéferson H. M. Santos, Lindomar G. De Sousa, Débora V. Franco, Willian G. Nunes, Hudson Zanin, Leonardo M. Da Silva
Fontes
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Electrochimica acta Vol. 295 (Fev., 2019), p. 302-315 |