Papers by Author: Tae Ho Kim

Abstract: The commercial nano-sized TiO2 powder (P25) coated with PtO2 powder by a sonochemistry method was immobilized on the foamed waste-glass substrates by using plasma spray coating technology. The immobilized TiO2-Pt coatings were applied to treat both green tide and red tide under illumination of an UV light. Their photocatalytic characterizations were evaluated as functions of the number of residual algae, transmission as well as pH value with illumination time. It’s found that the plasma sprayed Pt-doped TiO2 nanostructured coatings on foamed waste-glass showed higher photocatalytic activity, which was effective to treat the green tide and red tide.

Abstract: The phase and microstructure of four kinds of plasma sprayed TiO2 coatings (P25, ST, NK, KT) were characterized by XRD (X-ray Diffraction), FE-SEM (Field Emission Scanning Electron Microscope) and TEM ( Transmission Electron Microscopy). Their photocatalytic properties were discussed in relation to phase composition and microstructure. The FE-SEM observation results reveal that there are quite a number of nanoparticles on the surfaces of all four kinds of plasma sprayed TiO2 coatings, which provide photocatalytic reactive sites. Based on the observation results of FE-SEM and TEM, the microstructure schematic of plasma sprayed TiO2 coatings using nanoparticles as feedstock is suggested. The best photocatalytic property of P25 coating among the four plasma sprayed TiO2 coatings is attributed to the combination of its fine “cauliflower” structure and the highest anatase content.

Abstract: The commercial nano-sized TiO2 powder (P25) was immobilized on foamed waste-glass substrates by using the plasma spraying technology. The immobilized TiO2 coatings were applied to treat both the green tide and the red tide under illumination of an UV light. Their photocatalytic characterizations were evaluated as functions of the number of residual algae, transmission as well as pH value with illumination time. It was found that the plasma sprayed nano-TiO2 coatings on foamed waste-glass show a higher photocatalytic activity, which was effective to treat the green tide and the red tide.

Abstract: Plasma spraying technique was used to deposit thin TiO2-based photocatalytic coatings on a foamed aluminum. Before spraying, the composites of nano-TiO2 powder (P25) and nano- ZnO/CeO2/SnO2 powders were agglomerated into microsized powders by a spray-drying process. XRD, SEM, TEM, XPS and the photocatalytic activity evaluation by the decomposition of benzene were applied to characterize the starting powders and the coatings, respectively. The results showed that all the three plasma sprayed TiO2-based coatings were the mixture phases of anatase and rutile. The XPS spectra results revealed that the oxygen element was composed of three kinds of chemical states, i.e., crystal lattice oxygen, hydroxyl oxygen and physical-adsorbed oxygen. The plasma sprayed 90%TiO2-10%CeO2 coating and 90%TiO2-10%SnO2 coating exhibited similar photocatalytic activity, which was higher than that of 90%TiO2-10%ZnO coating.