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”.

Graphene is a very promising material for real applications due to its unique properties and special structure. The methods of graphene preparation include mechanical exfoliation, silicon carbide epitaxy, chemical vapor deposition, redox and laser-induced graphene (LIG). Among them, LIG is a very promising graphene preparation method due to its advantages such as low fabrication cost, simple fabrication and low environmental pollution.

Some researchers have conducted basic studies of LIG applications including hydrogen-generating electrodes, supercapacitors and various sensors. To date, however, no research has been published on the optimal parameter selection and the influence of these parameters on the properties of LIG.

Jang Il San, a researcher at the Institute of Nano Science and Technology, has investigated the effect of laser power and scanning speed on LIG formation when CO₂ laser is irradiated on polyimide films.

First, he developed a theoretical model to get temperature field distribution on the film when CO₂ laser is irradiated on a polyimide film. Then, he calculated the temperature distribution inside the laser beam focus spot at different laser powers and scanning rates using COMSOL Multiphysics. After that, he determined the laser power and scanning speed range for LIG formation, and prepared graphene samples accordingly.

The simulation of the temperature field on the polyimide film during LIG fabrication showed that the temperature at which graphene is formed is above 2 800K at the depth of about 0.025mm.

If further information is needed, you can refer to his paper “Effect of Laser Power and Scanning Speed on Properties of Laser-Induced Graphene” in “Proceedings of KUTIC-2025”.

As a kind of fibre, regular textile fabric is considered a porous medium composed of a lot of thread. Thread itself is also a porous medium. In other words, regular textile fabric corresponds to a large-pore porous medium composed of small-pore matrix (thread).

Heat and mass transfer problems in porous media have been studied in two categories: equilibrium and non-equilibrium. Some studies focused on the numerical simulation of the problems involving non-equilibrium heat and mass transfer.

Choe Song Gun, a section head at the Faculty of Thermal Engineering, has developed a mathematical model of fluid flow and non-equilibrium heat and mass transfer in porous media.

First, he presented governing equations for fluid, solid and porous regions and he paid special attention to moisture transfer from porous media to the surrounding moist air flow. Then, he described a CFD solution approach for spatially distributed temperature and moisture content in regular textile fabric during drying. User-Defined Scalar (UDS) and User-Defined Function (UDF) were used.

Finally, he conducted an unsteady simulation of drying of porous media placed in the 2D channel by using FLUENT, and analysed the effects of temperature and velocity at the inlet and the porosity and diffusion coefficient of porous media on drying.

For more information, please refer to his paper “CFD Simulation of Convective Drying of Regular Dual Porosity Media Under Local Non-Equilibrium” in “Proceedings of KUTIC-2025”.