• Journal of the Korean Ceramic Society
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• v.42 no.7 s.278
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• pp.461-468
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• 2005

Transparent TiO$_{2}$ sols were prepared by hydrothermal synthesis to heat Ti precursor solutions, from Ti hydroxides obtained with neutralizing aqueous TiOCl$_{2}$ solutions having various concentrations of NaCI by aqueous NaOH solution, in the autoclave at 120$^{\circ}C$ The photocatalytic abilities of glass beads coated with the sol for gaseous benzene were evaluated. As a result, it was found that due to the increase of brookite phase in TiO$_{2}$ by controlling the concentration of Na ion the optical absorption of TiO$_{2}$ increases toward long wavelength but that in the area of short wavelength becomes relatively low and consequently the photocatalytic performance of TiO$_{2}$ thin film for benzene gas rather decreases, compared to that of composite film of anatase and brookite phases. These results suggest that in order for coated TiO$_{2}$ thin film to have high dissociation performance for benzene gas it is effective to form anatase and brookite phases compositely in TiO$_{2}$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.5
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• pp.268-276
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• 2009

In this study, activated carbon (AC) was treated with ferric ion by a sol-gel method. The compound (Fe-AC) was employed for the preparation of Fe-activated carbon/$TiO_2$, (Fe-AC/$TiO_2$) composites. The prepared Fe-AC/$TiO_2$ composites were characterized with surface properties, structural crystallinity, elemental identification and photocatalytic activity. The SEM results showed that ferric compounds and titanium dioxide were fixed onto the AC surfaces. The XRD results showed that Fe-AC/$TiO_2$ composites mostly contained anatase phase. EDX showed the presence of C, O, and Ti with Fe peaks in all samples. Its photocatalytic degradation effect was evaluated with the degradation behavior of the methylene blue (MB) solution. MB degradation could be attributed to the synergetic effects of adsorption, photo-degradation of $TiO_2$ and photo-Fenton of Fe component. The degradation rate for this photocatalysis was evaluated as a function of the concentration of the dye, the amount of $TiO_2$ and the pH. Photocataytic activity is good at activity pH.

• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.561-567
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• 2009

The Fe-ACF/$TiO_2$ composites were prepared by a sol-gel method and were characterized by nitrogen adsorption, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Energy Dispersive X-ray (EDX). The Fe-ACF/$TiO_2$ composites were developed for the decomposition of organic dyes by using a UV lamp. The decomposition effect was investigated under various conditions, such as three selected non-biodegradable organic dyes like Methylene Blue (MB), Methyl Orange (MO), Rhodamine B (Rh.B), and in the presence of Fe and hydrogen peroxide ($H_2O_2$). The photocatalytic activity was derived from possible combination effects, such as (1) adsorption of ACF, (2) generation of electron/hole by $TiO_2$, (3) photo-Fenton reaction of Fe, and (4) oxidation of $Fe^{2+}\;to\;Fe^{3+}\;by\;H_2O_2$.

• Journal of the Korean GEO-environmental Society
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• v.11 no.10
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• pp.33-39
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• 2010

A self-organized nano-structured, photocatalytic $TiO_2$ membrane with large surface area of anatase crystallites was successfully fabricated by anodization. The nano-structured anodized $TiO_2$ membrane was characterized using EDX, SEM and XRD techniques and the effect of electrolyte type and concentration to fabricate $TiO_2$ metal membrane was also investigated. Regular nano tubular arrays were obtained By the EDX, SEM and XRD patterns, the anodized $TiO_2$ membrane showed the enhanced photocatalytic properties of anatase phase. Photocatalytic activities of fabricated $TiO_2$ metal membrane was also experimentally investigated as model compound of humic acid.

• Membrane Journal
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• v.28 no.3
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• pp.143-156
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• 2018

In this review article, hybrid water/wastewater treatment processes of membrane and photocatalyst were summarized from papers published in various journals. It included (1) membrane photoreactor (MPR), (2) fouling control of a membrane coupled photocatalytic process, (3) photocatalytic membrane reactors for degradation of organic pollutants, (4) integration of photocatalysis with membrane processes for purification of water, (5) hybrid photocatalysis and ceramic membrane filtration process for humic acid degradation, (6) effect of $TiO_2$ nanoparticles on fouling mitigation of ultrafiltration membranes for activated sludge filtration, (7) hybrid photocatalysis/submerged microfiltration membrane system for drinking water treatment, (8) purification of bilge water by hybrid ultrafiltration and photocatalytic processes, and (9) Hybrid water treatment process of membrane and photocatalyst-coated polypropylene bead.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2935-2940
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• 2014

Monodispersed $Bi_2O_2CO_3$ nanoplates with an average width of 320 nm and thicknesses of 50-90 nm were successfully synthesized by a simple solvothermal method in a mixture solution of polyethylene glycol and $H_2O$. The obtained nanoplates were characterized by means of XRD, FT-IR, SEM and TEM. The effect of surfactant sodium dodecyl benzene sulfonate on the morphology of $Bi_2O_2CO_3$ product was investigated. Under simulated solar light irradiation, $Bi_2O_2CO_3$ nanoplates exhibited superior photocatalytic activities towards the degradation of RhB as well as high chemical stability upon cycling photocatalytic test. The nanoplates also showed promising photodegradation ability for eliminating refractory pollutant of phenol. The excellent photocatalytic performance of $Bi_2O_2CO_3$ nanoplates as compared with P25-$TiO_2$ endows them as promising high efficiency photocatalysts.

• Journal of Magnetics
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• v.21 no.1
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• pp.46-50
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• 2016

$Fe_2O_3/TiO_2$ nanocomposite were successfully synthesized by co-precipitation method using $Fe(NO_3)_3{\cdot}9H_2O$ and $Ti(SO_4)_2$ as raw materials. Structural and textural features of the mixed oxide samples were characterized by X-ray diffractometer, field emission scanning electron microscopy and energy-dispersive X-ray. The effects of initial concentration of oxytetracycline (OTC), different competitive ions and organics on the photocatalytic degradation rate of OTC by the $Fe_2O_3/TiO_2$ nanocomposite were analyzed under UV and visible light irradiation. The results indicate that the optimized initial concentration of OTC was 50 mg/L to achieve the best photocatalytic efficiency. $Cu^{2+}$, $NH_4{^+}$, $C_3H_8O$ and EDTA in the aqueous suspension were found to suppress the degradation rate of OTC, whereas the effect of $NO_3{^-}$ and $H_2C_2O_4$ can be ignored.

• Journal of Environmental Science International
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• v.13 no.10
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• pp.921-928
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• 2004

The photocatalytic decolorization of Rhodamine B (RhB) was studied using immobilized $TiO_2$ and fluidized bed reactor. Immobilized $TiO_2$(length: 1$\~$2 mm, width: 1$\~$3 mm, thickness: 0.5$\~$2 mm) onto silicone sealant was employed as the photocatalyst and a 30 W germicidal lamp was used as the light source and the reactor volume was 4.8 L. The effects of parameters such as the amounts of photocatalyst, initial concentration, initial pH, superficial velocity, $H_2O_2$ and anion additives. ($NO_3^{-},\;SO_4^{2-},\;Cl^{-},\;CO_3^{2-}$) The results showed that the optimum dosage of the immobilized $TiO_2$ were 87.0 g/L. Initial removal rate of RhB of the immobilized $TiO_2$ was 1.5 times higher than that of the powder $TiO_2$ because of the adsorption onto the surface of immobilized $TiO_2$ In the conditions of acidic pH, initial reaction rate was increased slowly and reaction time was shorted. The effect of anion type on the reaction rate was not much.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2255-2259
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• 2012

Aggregation of titania nanotubes (TNTs) fabricated by hydrothermal method were calcined in air and dry nitrogen; Changes in morphology and crystallinity of the nanotubes were studied by means of TEM, EDX, and XPS. EDX patterns and XPS spectra proved that there were a certain densities of oxygen vacancies in TNTs annealed in $N_2$. The photocatalysis experiments revealed TNTs/$N_2$ possesses significantly higher photocatalytic efficiency than TNTs annealed in dry air to degrade methylene blue. The correlation between oxygen vacancies and photocatalytic property may be attributed to: 1) oxygen vacancies might have affected results on water molecules adsorption and increase of the hydroxyl concentration; and 2) oxygen vacancies resulted in some changes in electronic structure of TNTs/$N_2$ aggregation and Fermi level extends into the conducting band.

• Journal of the Korean Ceramic Society
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• v.45 no.1
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• pp.43-47
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• 2008

The photocatalyst of $TiO_2$ coated on a fly ash composites (TCF) was prepared from precipitant dropping method to remove the acetaldehyde by photocatalytic reaction. The TCF were characterized by crystal aize, crystal structure and specific surface area. The photodegradation of acetaldehyde has been investigated using a UV-illuminated fixed photocatalytic reactor with TCF catalyst and P-25 catalyst in gas phase. The effect of photodegradation reaction conditions, such as initial concentration of acetaldehyde, concentration of oxidant in mixed gas and the light intensity on the photodegradation of acetaldehyde were investigated. P-25 catalyst showed the highest photodegradation of acetaldehyde and anatase $TiO_2$ coated TCF showed higher decomposition rate than rutile coated TCF. The photodegradation rate of acetaldehyde increased with the decrease of flow rate, initial concentration of acetaldehyde ($C_i$) and water vapor, however, it was increased with the increas of UV light intensity. The optimum conditions were weight of TCF=10 g, flow rate=50 ml/min $C_i$=100 ppm, concentration of oxygen=20%, concentration of water vapor=100 ppm.