• Journal of the Korean institute of surface engineering
• /
• v.40 no.3
• /
• pp.113-116
• /
• 2007

Titanium dioxide ($TiO_2$) films were deposited by RF reactive magnetron sputtering on non-alkali glass and single crystal MgO (100) substrate at substrate temperature of $400^{\circ}C$. Micro structures of $TiO_2$ films were investigated by XRD, FE-SEM, and Pole figure measurements. $TiO_2$ films deposited on glass substrate showed preferred orientation of anatase (101), whereas $TiO_2$ films deposited on the MgO single crystal substrate showed hetero-epitaxial anatase (100). $TiO_2$ film grown on MgO substrate showed higher photoctalytic activity than that of glass substrate.

• Journal of the Korean Ceramic Society
• /
• v.54 no.4
• /
• pp.308-313
• /
• 2017

In this study we examined the photo-degradation efficiency of $CoS_2-G-TiO_2$ nanocomposites under visible light irritation using Reactive Black B (RBB) as standard dye, $CoS_2-G-TiO_2$ nanocomposites synthesized by facial microwave assist technique, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopic analysis. Our results show the efficiency of the $CoS_2-G-TiO_2$ ternary nanocomposite is better than $CoS_2-G$ and $TiO_2-G$ nanocomposite. The degradation efficiency of $CoS_2-G-TiO_2$ nanocomposite was found approximately 89% of Reactive Black B (RBB) degraded after 180 min. Our results will open new way for the development of a new ternary nanocomposite photocatalytic application.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.3
• /
• pp.336-339
• /
• 1999

Photo-excited $TiO_2$ surface has a strong ability to induce various chemical reactions. Our study concentrates mainly on the utilisation of light energy to induce reactive radicals for environmental protection application. For instance, we have successfully used TiO$_2$ to break down foul smelling substances in air. In order to retain and separate the $TiO_2$ catalyst from the reactants and products, $TiO_2$ was immobilised by fixing onto various substrates. $TiO_2$ catalyst coated onto glass, wall paper and painted panel was found to show significant deodorising effect. The deodorising effect continues as long as$TiO_2$ is exposed to light irradiation.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.1169-1174
• /
• 2013

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since $TiO_2$ had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped $TiO_2$ were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction ${\theta}-2{\theta}$ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol% Ag-doped $TiO_2$ layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.59-66
• /
• 2005

[ $TiO_2$ ] was deposited by DC magnetron sputtering on glass surface under various sputtering parameters such as discharge power($0.6{\sim}5.2\;kW$, substrate temperature($R.T{\sim}350^{\circ}C$), Ar and $O_2$ flow ratio with $0{\sim}50\;sccm$($Ar+O_2$ 90 sccm) and about 1 mtorr of pressure. TiO-N thin film was prepared under same sputtering conditions for $TiO_2$ thin film except flow ratio($Ar+O_2+N_2$ 90 sccm). The sheet resistance of thin films deposited under these parameters was measured to analyze electronic characteristic and thin film's thickness(${\alpha}$-step), surface roughness(AFM) and formation construction(FE-SEM, XRD) were also measured to draw optimal sputtering parameters. In order to evaluate photo-activity of thin film($TiO_2$, TiO-N) made in optimal parameters for removal of pollutants, toluene among VOCs and Suncion Yellow among reactive dyes were chosen to probe organic compounds for photo-degradation. It was shown that the photo-catalytic thin films had a significant photo-activation for the chosen contaminants and especially TiO-N thin film showed maximum efficiency of 33% for toluene(5 ppm) removal in visible-light range.

• Journal of Magnetics
• /
• v.12 no.2
• /
• pp.81-83
• /
• 2007

Etching of NiFe films covered with an organic photo-resist or Ti was successfully performed by an inductively coupled plasma-reactive ion etching (ICP-RIE) system using $CHF_3/O_2/NH_3$ discharges exchanging $CHF_3$ for $CH_4$ gas gradually. Experimental results showed that the organic photo-resist mask can be applied to the NiFe etching. In the case of the Ti metal mask, it was found that the etching-selectivity Ti against NiFe was significantly varied from 7.3 to ${\sim}0$ by changing $CHF_3/CH_4/O_2/NH_3$ to $CH_4/O_2/NH_3$ discharges used in the ICP-RIE system. These results show that the present RIE of NiFe was dominated by a chemical reaction rather than a physical sputtering.

• Journal of Korean Ophthalmic Optics Society
• /
• v.10 no.3
• /
• pp.185-191
• /
• 2005

Photo-reactive $TiO_2$ thin films on soda-lime-silica slide glass were prepared by spin coating technique with a Ti-naphthenate precursor. Optical, structural and photo-catalytic properties of the films after annealing at $500^{\circ}C{\sim}600^{\circ}C$ were evaluated. As increase with annealing temperature, absorption bands and total transmittance of the films showing an average transmittance (about 80%) at visible spectra range were shifted to UV spectra range and slightly decreased. Refractive index and thickness of the films were increased from 2.16 to 2.63 and decreased from 484 nm to 439 nm, respectively, with increase of annealing temperature. Anatase phase was visible at all annealing temperature. More rougher surface structure was obtained at $600^{\circ}C$ than those of films annealed at $500^{\circ}C$ and $550^{\circ}C$. The hydrophilic conversion was found within 45 min by UV stimulation and optical activation was UVC>UVA>UVB at the case of $500^{\circ}C{\sim}550^{\circ}C$ and UVA>UVC>UVB at the annealing temperature of $600^{\circ}C$. The lowest initial contact angle was obtained at $600^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.6
• /
• pp.1589-1595
• /
• 2010

In order to effective degradation of organic dye both under visible light or ultrasonic irradiation, the MWCNTs (multiwalled carbon nanotube) deposited with Fe and $TiO_2$ were prepared by a modified sol-gel method. The Fe/$TiO_2$-MWCNT catalyst was characterized by surface area of BET, scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) and ultraviolet-visible (UV-vis) spectroscopy. The low intensity visible light and low power ultrasound was as an irradiation source and the methylene blue (MB) was choose as the model organic dye. Then degradation experiments were carried out in present of undoped $TiO_2$, Fe/$TiO_2$ and Fe/$TiO_2$-MWCNT catalysts. Through the degradation of MB solution, the results showed the feasible and potential use of Fe/$TiO_2$-MWCNT catalyst under visible light and ultrasonic irradiation due to the enhanced formation of reactive radicals as well as the possible visible light and the increase of ultrasound-induced active surface area of the catalyst. After addition of $H_2O_2$, the MB degradation rates have been accelerated, especially with Fe/$TiO_2$-MWCNT catalyst, in case of that the photo-Fenton reaction occurred. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of Fe/$TiO_2$-MWCNT catalyst.

• Transactions of the Korean hydrogen and new energy society
• /
• v.21 no.4
• /
• pp.301-306
• /
• 2010

The present work is performed to photocatalytically reduce Cr(VI) by means of metal deposited anodized $TiO_2$ tubes, which are prepared by anodization of Ti foil followed by metal deposition. Stably immobilized photo-reactive materials are favored in the field of detoxification in a conventional aqueous medium, preventing gradual loss of efficiency and process malfunction due to detachment of the materials. The prepared samples are characterized by SEM, TEM, EDAX, and photocurrent. The metal deposited-$TiO_2$ electrode shows higher efficiency for Cr(VI) reduction (ca. 20%) and higher ability for adsorption (4~5 times) than pure one.

• Journal of the Korean Ceramic Society
• /
• v.47 no.2
• /
• pp.169-176
• /
• 2010

The Fe-treated CNT/$TiO_2$ photocatalysts mixed with anatase and rutile phase have been developed for the decomposition of non-biodegradable different organic dyes like methylene blue (MB), rhodamine B (Rh.B), and methyl orange (MO) in two conditions as ultraviolet and visible light respectively. The results indicate that all the Fe-CNT/$TiO_2$ composites proved to be more efficient photocatalysts since degradation of MB at higher reaction rates, tthe decomposition rate of different dyes increases with an increase of $Fe^{3+}$ concentration in composites the highest rate of decomposition of different dyes was noted under UV irradiation. These results can indicate that the large CNT network is facilitate the electron transfer and strongly adsorb dye molecules on the texted photocatalysts, iron is reactive in the photo-Fenton process resulting in high production of OH radicals and also high activity of the photocatalyst. And Fe particles can generate more photoinduced electrons to conduction band of $TiO_2$ under visible light irradiation. The composites of Fe-CNT/$TiO_2$ photocatalysts synthesized by a sol-gel method were characterized by BET, TEM, SEM, XRD and EDX.