Mechanisms and kinetics of electrode processes at bismuth and antimony film and bare glassy carbon surfaces under square-wave anodic stripping voltammetry conditions

Abstract

a b s t r a c tMechanism and kinetics of anodic stripping electrode processes of Zn(II), Cd(II) and Pb(II) at bismuth (BiFE) and antimony (SbFE) film as well as bare glassy carbon (GCE) electrodes have been studied with respect to our recent published theoretical considerations developed for square-wave voltammetry (SWV). Mechanistic aspects of electrode reactions have been elucidated by a qualitative comparison of simulated and experimental data for three different electrode reaction mechanisms, i.e. simple anodic stripping mechanism, anodic stripping mechanism coupled with adsorption of metal analyte ions, and mechanism affected by interactions within the particles of the metal deposit on the electrode surface. The electrode kinetics has been estimated by the method of quasireversible maximum and by analyzing the peak potential separation between forward and backward SW components, under variation of the SW amplitude. Electrode mechanisms and kinetics are different at bismuth compared to antimony film electrodes. The electrode reactions of Pb(II) and Cd(II) at BiFE involve adsorption phenomena, while electrode processes of all three analytes are free of adsorption at SbFE. At BiFE, the electron transfer standard rate constants of all three analytes are quite comparable, ranging within the interval from 1 to 3 cm s −1 . At SbFE the electrode kinetics of Cd(II) and Pb(II) are almost the same, while the electrode reaction of Zn(II) is significantly slower. Our results showed that the kinetics of all examined electrode reactions are slower at SbFE as compared to those observed at BiFE.

Deciphering lead and cadmium stripping peaks for porous antimony deposited electrodes

“…This is consistent with the observations found in the literature. The researchers explained this behavior on the basis of the difference in relative affinity of the two metals with antimony [11].…”

“…Doped metal enhances the current to voltage signal for the analytes and can detect heavy metals present in water up to ppb levels. Mercury [3][4][5][6][7][8], bismuth [9][10][11], gold [12][13][14], platinum [15] and tin [16] are examples of active metals reported in literature. Mercury and bismuth are usually used because of their superior properties.…”

Desenvolvimento, caracterização e aplicações de folhas condutoras de grafite como eletrodos de trabalho

“…(B) Curva de calibração obtida. Condições experimentais: Eletrólito: H 2 SO 4 0,1 mol L -1 ; tempo de adsorção 120 s em OCP (potencial do circuito aberto, do inglês open circuit potencial); frequência: 25 Hz; incremento de potencial: 8 mV; amplitude de pulso: 30 mV; tempo de equilíbrio: 10 s. folha de grafite são semelhantes a outros eletrodos a base de carbono e são afetados pela adsorção, difusão e interações atrativas (MIRCESKI et al, 2012(MIRCESKI et al, , 2013.…”

Determinação de manganês em etanol combustível por voltametria de redissolução

“…O eletrodo de carbono vítreo geralmente é usado como suporte para filme de bismuto devido a suas propriedades mecânicas, elétricas e a facilidade de operação. A modificação de um eletrodo com filme de bismuto foi desenvolvida como uma alternativa para substituir os eletrodos a base de mercúrio [30,31].…”

“…Porém, um estudo envolvendo diferentes substratos como carbono vítreo, grafite e pasta de carbono, mostrou que o substrato influencia na resposta analítica do filme. Neste estudo, o carbono vítreo apresentou a melhor resposta analítica para os íons Cd 2+ e Pb 2+ [31].…”