Recently, PbO2 electrodes with high oxygen overpotential, good electrical conductivity and electrocatalytic property have been widely used as anode in electrochemical industries such as electrowinning of metals, lead acid batteries, analytical sensors, electrochemical synthesis of peroxides and electrochemical treatment of wastewater, etc.
PbO2 is divided into two types, namely, α-PbO2 in the orthorhombic form and β-PbO2 in the tetragonal form. The anode material PbO2 is prepared by electrodeposition. α-PbO2, which is mainly electrodeposited in alkaline electrolyte, is used as an intermediate layer to enhance the performance of β-PbO2 on the substrate. β-PbO2 electrodeposited in acid solutions has good electrochemical properties such as electrical conductivity and active surface area, and it is considered as an alternative anode material for platinum or RuO2 electrodes. Pure β-PbO2 electrodes have not been durable when used at high voltages because they have low electrocatalytic activity. Therefore, many studies have been carried out to improve the stability, service life and adhesion of PbO2 electrodes. However, few papers have reported the changes in the stability, service life, electrochemical activity, etc. of electrodes depending on dispersants. Dispersants are often used in electrodeposition because they improve the surface property and adhesion of PbO2 layers.
Paek Yong Sok, a researcher at the Faculty of Chemical Engineering, prepared stainless steel (SS)/α-PbO2/β-PbO2 electrodes with improved surface states and electrocatalytic activity using cerium and dispersants sodium dodecyl sulfate (SDS) and polyvinyl alcohol (PVA), and evaluated the electrochemical properties of electrodes depending on the dispersants. He determined the service life of electrodes by accelerated life tests and electrooxidized Ce3+ in rare earth sulfate solution, using the prepared SS/α-PbO2/β-PbO2 electrodes.
The electrode prepared by the addition of SDS and PVA together had the longest life time 525h. Using the SS/α-PbO2/β-PbO2 electrode, 95% of cerium was oxidized at a current density of 20mA/cm2 for 37h. The current efficiency was more than 87% and the power consumption was the lowest, 1.8kW･h/kg.
For more information, please refer to his paper “Preparation of Stainless Steel/α-PbO2/β-PbO2 Electrode and its Application for Electrooxidation of Cerium” in “Proceedings of KUTIC-2025”.