Publicação: Thermal and electrochemical studies of Cu(II) 8-hydroxyquinoline organophilic montmorillonite
Carregando...
Arquivos
Data
Orientador
Coorientador
Pós-graduação
Curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Editor
Tipo
Artigo
Direito de acesso
Acesso aberto
Resumo
The thermal and electrochemical behavior of montmorillonite clay-8-hydroxyquinoline (8-HQ) film was studied in the absence and presence of aqueous Cu(II) ions. The suggested formation of the ternary complex type: {Pt/[> Si–O]n[Cu(II)(OH2)n(8-HQ)k]}3−n−k, with thermal stability up to 350 °C, was studied, based on UV-spectroscopy, thermal (DTG-DSC, molecular fluorescence and XRD. The Pt/binary composite film (SWy-1:8-HQ) interphase composed of montmorillonite (SWy-1) with 8-hydroxyquinoline (8-HQ) was investigated by electrochemical techniques analyzing the cyclic voltammograms (CVs) obtained at different scan rates (v) and copper(II) ion concentrations. The mechanical stability of the thin films was demonstrated by performing 80 successive voltammetric cycles. Two pairs of redox peaks, indicated by peaks A/D and C/B were observed. For Cu(II) ions in solution, the log ip × log v relationships showed processes controlled by adsorption, peaks A/D, and by diffusion, peaks C/B. The analysis of ip/v1/2 and ipa/ipc versus v suggested two homogeneous coupled reactions, being both reversible and fast kinetic chemical reactions, associated to the mechanisms chemical-electrochemical (CE) and electrochemical-chemical (EC), respectively. The modified electrode showed a good sensitivity to low concentrations of Cu(II) ions, which opens the possibility of being used in chemical analysis.
Descrição
Palavras-chave
Cu(I)/Cu(II) redox species, Organic montmorillonite composites, Reversible coupled reactions, TG–DTA simultaneous, Cu(II) ions
Idioma
Inglês
Como citar
Journal of Thermal Analysis and Calorimetry, v. 131, n. 1, p. 799-810, 2018.
