Photoelectrochemical properties of the lead electrode during anodic oxidation in sulfuric acid solution

Journal Article · Sat Oct 01 04:00:00 EDT 1977 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2133105· OSTI ID:5073908

Pavlov, D; Zanova, S; Papazov, G

During oxidation of a lead electrode in a H/sub 2/SO/sub 4/ solution at potentials between -200 and +900 mV (vs. Hg/Hg/sub 2/SO/sub 4/ electrode), an anodic layer containing tet-PbO and PbSO/sub 4/ is formed. When oxidation is conducted in the dark, PbO does not display photoelectrochemical properties. In order to constitute a photoelectrochemical system the electrode has to be photoactivated by illumination with a given quantity of light at potentials more positive than 0 mV. In this case the PbO layer converts into a PbO/sub n/ layer with 1 < n< 2. When a photoactivated electrode is illuminated, three types of photoelectrochemical processes occur. The first type leads to photoionization of lead oxide and OH/sub ad/ and O/sub ad/ are evolved at the PbO/sub n//solution interface. These processes take place at potentials between -400 and 0 mV. The second kind occurs at potentials more positive than 0 mV and leads to the formation of PbO/sub n/ and photoactivation of the oxide. The mechanism according to which these processes take place includes the formation of Pb/sup 4 +/ ions in the oxide via photochemical reactions, reconstruction of the unit cell of PbO into that of PbO/sub 2/ containing oxygen vacancies, and reactions of these vacancies with water with the subsequent formation of PbO/sub n/. The third kind of photoprocesses leads to photolysis of water at the surface of the PbO/sub n/ layer with formation of O/sub 2/. 9 figures.

• Research Organization: Central Lab. of Electrochemical Power Sources, Sofia
• OSTI ID: 5073908
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 124:10; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250903* -- Energy Storage-- Batteries-- Materials
Components
&amp; Auxiliaries
ANODES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELECTRIC BATTERIES
ELECTROCHEMICAL CELLS
ELECTRODES
ENERGY STORAGE SYSTEMS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
LEAD COMPOUNDS
LEAD OXIDES
LEAD SULFATES
LEAD-ACID BATTERIES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
REACTION KINETICS
SULFATES
SULFUR COMPOUNDS
SULFURIC ACID