scholarly journals Studying the effects of bismuth on the electrochemical properties of lead dioxide layers by using the in situ EQCM technique

2020 ◽  
Vol 24 (11-12) ◽  
pp. 2733-2739
Author(s):  
Balázs Broda ◽  
György Inzelt
Keyword(s):  
Sulfuric Acid ◽  
Quartz Crystal ◽  
Lead Dioxide ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Lead Sulfate ◽  
Acid Media ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of ◽  
Thick Lead

Abstract The charge-discharge characteristics and the aging mechanism of PbO2 layers doped with bismuth in contact with sulfuric acid solutions were studied by using combined cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) techniques. For this purpose, thick lead dioxide layers (non-doped and doped with Bi) were electrodeposited on gold substrate from aqueous solutions of Pb(NO3)2 dissolved in nitric acid and they were investigated in sulfuric acid media. Based on the electrochemical and the mass change responses, it is concluded that during the electrodeposition, bismuth influences the structure of the PbO2 formed. Bi(III) also inhibits the oxidation of lead sulfate and affects the reduction kinetics of lead dioxide. During successive cyclization (aging), the presence of bismuth accelerates the hydration of PbO2.

scholarly journals Investigation of the electrochemical behaviour of lead dioxide in aqueous sulfuric acid solutions by using the in situ EQCM technique

2019 ◽  
Vol 24 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Balázs Broda ◽  
György Inzelt
Keyword(s):  
Cyclic Voltammetry ◽  
Sulfuric Acid ◽  
Electrochemical Behaviour ◽  
Lead Dioxide ◽  
Lead Sulfate ◽  
Main Reaction ◽  
Cyclic Voltammogram ◽  
Acid Solutions ◽  
Acid Media ◽  
Sulfuric Acid Solutions

AbstractThe charge-discharge characteristics and the aging mechanism of PbO2 layers in contact with sulfuric acid solutions of different concentrations (1.5–5.0 M) were studied by using combined cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) techniques. For this purpose, thick lead dioxide layers were electrodeposited on gold substrate from aqueous solutions of Pb(NO3)2 dissolved in nitric acid. Based on the electrochemical and the mass change responses, it was found that in more concentrated solutions of H2SO4, the main reduction reaction was the transformation of lead dioxide to lead sulfate. However, in less concentrated sulfuric acid media, the transformation of lead dioxide to lead(II) ion became the main reaction. These Pb2+ ions transformed into lead sulfate crystals later by a chemical reaction. Because the electrochemical oxidation of lead sulfate is less favourable in sulfuric acid medium of higher concentrations, thus, PbO2 layers cannot be tested by continuous cyclization, which is necessary to study their aging parameters. Therefore, a delay step before each cyclic voltammogram was applied while the non-conductive lead sulfate dissolves or alternatively, by applying a pre-oxidation step prior to each cyclic voltammetry experiment to produce electrochemically significant amount of lead dioxide which can be reduced during the following negative potential sweep.

Kinetics of reduction of U(VI) with zinc amalgam in sulfuric acid solutions

2015 ◽  
Vol 57 (1) ◽  
pp. 31-35 ◽  
Author(s):  
V. N. Momotov ◽  
E. A. Erin ◽  
V. M. Chistyakov
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Zinc Amalgam ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of ◽  
Kinetics Of Reduction
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