PURPOSES : The purpose of this study was to analyze the effect of reducing nitrogen oxide concentration in a photocatalyst (titanium dioxide) using statistical methods such as the Anderson-Darling test. METHODS : To compare and analyze the effect of reducing the nitrogen oxide concentrations in titanium dioxide, titanium dioxide was applied to the public road, and data acquisition in terms of nitrogen oxide concentration was conducted from roads with/without applying titanium dioxide (test section and reference section, respectively). Then, the probabilities of occurrence of nitrogen oxide concentrations in the test and reference sections were estimated and compared using the Anderson-Darling test. RESULTS : According to the comparison and analysis of probabilities in the nitrogen oxide concentration of the test and reference sections, the probabilities of nitrogen oxide concentration on December 4th were estimated as ‘High’ (17.5%, 37.9%), ‘Moderate’ (30.5%, 40.8%), and ‘Low’ (52.0%, 21.3%), respectively, and on December 5th, as ‘High’ (20.6%, 39.1%), ‘Moderate’ (26.2%, 33.0%), and ‘Low’ (53.2%, 27.9%), respectively. In addition, the probabilities of nitrogen oxide concentration in the test and reference sections were analyzed on December 6th as ‘High’ (16.5%, 36.8%), ‘Moderate’ (27.9%, 38.5%), and ‘Low’ (55.6%, 24.8%), respectively. CONCLUSIONS : Based on the results of this study, in the test section with application of titanium dioxide, the nitrogen oxide concentration was found to have a low probability, and in the reference section, the nitrogen oxide concentration was found to be higher than that in the test section. Therefore, it can be concluded that titanium dioxide applied to road facilities has a nitrogen oxide reduction effect.

Water electrolysis is a representative electrochemical process to generate hydrogen gas together with oxygen gas by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as electrode binder materials, in addition to polymer electrolyte membrane materials for water electrolysis to generate hydrogen and oxygen gases with a high purity simultaneously. PFSA binder materials act as physical supports for inorganic catalyst materials in both electrodes. The binder materials play role in transporting protons for hydrogen gas and oxygen gas evolution reaction in the cathode and the anode, respectively. In this study, PFSA ionomers with different chemical architectures and equivalent weights were used as binder materials for water electrolysis. The structure property performance relationship was disclosed.

Porous graphites were synthesized by removing the template in HF after cabothermal conversion for 3 h at 900 ℃, accompanied by intercalations of pyrolyzed fuel oil (PFO) in the interlayer of Co or Ni loaded magadiite. The X-ray powder diffraction pattern of the porous graphites exhibited 00l reflections corresponding to a basal spacing of 0.7 nm. The particle morphology of the porous graphites was composed of carbon plates intergrown to form spherical nodules resembling rosettes like a magadiite template. TEM shows that the cross section of the porous graphites is composed of layers with very regular spaces. In particular, crystallization of the porous graphite was dependent on the content of Co or Ni loaded in the interlayer. The porous graphite had a surface area of 328-477 m2/g. This indicates that metals such as Co and Ni act as catalysts that accelerate graphite formation.

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of WO3 nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of WO3 are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on WO3 nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert’s law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

NiO catalysts/Al2O3/FeCrAl alloy foam for hydrogen production was prepared using atomic layer deposition (ALD)and subsequent dip-coating methods. FeCrAl alloy foam and Al2O3 inter-layer were used as catalyst supports. To improve thedispersion and stability of NiO catalysts, an Al2O3 inter-layer was introduced and their thickness was systematically controlledto 0, 20, 50 and 80nm using an ALD technique. The structural, chemical bonding and morphological properties (includingdispersion) of the NiO catalysts/Al2O3/FeCrAl alloy foam were characterized by X-ray diffraction, X-ray photoelectronspectroscopy, field-emission scanning electron microscopy and scanning electron microscopy-energy dispersive spectroscopy. Inparticular, to evaluate the stability of the NiO catalysts grown on Al2O3/FeCrAl alloy foam, chronoamperometry tests wereperformed and then the ingredient amounts of electrolytes were analyzed via inductively coupled plasma spectrometer. We foundthat the introduction of Al2O3 inter-layer improved the dispersion and stability of the NiO catalysts on the supports. Thus, whenan Al2O3 inter-layer with a 80nm thickness was grown between the FeCrAl alloy foam and the NiO catalysts, it indicatedimproved dispersion and stability of the NiO catalysts compared to the other samples. The performance improvement can beexplained by optimum thickness of Al2O3 inter-layer resulting from the role of a passivation layer.

The influence of sulfate on the selective catalytic reduction of on the Ag/ catalyst was studied when was used as a reducing agent. Various preparation methods influenced differently on the activity. Among the methods, cogelation precipitation gave best activity. When sulfates were formed on the surfaces of samples prepared by impregnated and deposition precipitation, activity was enhanced as long as suitable forming condition is satisfied. The major sulfate formed in Ag/ catalyst was the aluminum sulfate and it seems that this sulfate acted as a promoter. When Mg was added to the Ag/ catalyst it promoted activity at high temperature. Intentionally added sulfate also enhanced activity, when their amount was confined less than 3 wt%.

TiO2광촉매릉 반응성 스퍼터링법을 이웅하여 박막으로 제조하고 유기물 및 살균실험을 통하여 미세조직이 광촉매 효율에 미치는 영향을 조사하고자 하였다. 광촉매 효율측정을 위하여 페놀분해실험 및 E.coli 078을 이용한 살균실험을 행하였다. TiO2박막에 의한 페놀분해실험 시, 전자수용체인 산소의 공급에 의하여 분해효율이 2배까지 증가하였다. E.coli 078분해실험의 경우, 광촉매 TiO2박막을 사웅하여 살균하였을때 UV만 조사하여 살균하였을 경우 보다 분해효율이 최고 70% 이상 증가하였다. 페놀분해실험과 E.coli 078 살균실험 결과 저결정성 박막의 경우 분해능이 매우 미약하였으며, 표면조도가 높고 결정성이 우수한 박막의 경우에 높은 광촉매 효율을 나타내어TiO2박막의 광촉매 효과는 표면형상과 결정성이 매우 중요한 인자로 작용하였다.

산화티탄의 광촉매 반응을 이용하여 휘발성 유기화합물(VOC)를 분해제거 하기 위하여 산화티탄을 glass bead에 sol-gel법으로 코팅하였다. 코팅막의 물성은 XRD, BET, SEM을 통해 분헉하였으며, 산화티탄이 galss bead를 채운 실험실규모의 광촉매 반응기를 이용 VOC중 벤젠 및 TCE 가스의 광촉매반응에 의한 분해효율에 대해 연구 컴토하였다. 반응기내의 잔류시간에 따른 가스농도 차이를 gas chromatography로 비교 분석하여 그 분해효율을 계산하였다. 이와 같은 정적인 상태의 실험결과, 400ppmv의 농도의 TCE인 경우 80%의 분해효율을 얻었으며, 50ppmv에서 300ppmv 농도의 벤젠인 경우 65%의 분해효율을 얻었다.

Background : Panos extract is a mixture of four Panax plant extracts namely Dendropanax morbifera, Panax ginseng, Acanthopanax senticosus and Kalopanax septemlobus. We intended to use Panos extract for ZnO nanoparticles(NPs) synthesis and application for waste water treatment. Methods and Results : In the present study, we have synthesized Panos ZnO nanoparticles via co precipitation method. Characterization of the NPs has been done using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and UV-Visible spectroscopy. An average of 75% efficacy in degrading the methylene blue dye has been observed. The nanoparticles showed antibacterial activity against E. coli and S. aureus. Conclusion : The results shows that Panos ZnO NPs can be a potential eco-friendly and economical tool for waste water management in the current scenario where there an intense urge to remediate the polluted environment through novel approaches such as Nanobiotechnology.

In this study, reaction model and reactions rate accelerated by o-iodosobenzoate ion(IB⊖) on hydrolysis reaction of p-nitrophenyl valate(NPV) using ethyl tri-octyl ammonium mesylate(ETAMs) for quaternary ammonium salts, the phase transfer catalysis(PTC) reagent, were investigated. The effect of IB⊖ on hydrolysis reaction rate constant of NPV was weak without ETAMs solutions. Otherwise, in ETAMs solutions, the hydrolysis reactions exhibit higher first order kinetics with respect to the nucleophile, IB⊖, and ETAMs, suggesting that reactions are occurring in small aggregates of the three species including the substrate(NPV), whereas the reaction of NPV with OH⊖ is not catalyzed by ETAMs. Different concentrations of NPV were tested to measure the change of rate constants to investigate the effect of NPV as substrate and the results showed that the effect was weak. This means the reaction would be the first order kinetics with respect to the nucleophile. This behavior for the drastic rate-enhancement of the hydrolysis is referred as 'Aggregation complex model' for reaction of hydrophobic organic ester with o-iodosobenzoate ion(IB⊖) in hydrophobic quarternary ammonium salt(ETAMs) solutions.

This study is mainly focused on micellar effect of cetylpyridinium chloride(CPyCl) solution including alkylbenzimidazole( R-BI) on dephosphorylation of diphenyl-4-nitrophenylphosphinate(DPNPIN) in carbonate buffer(pH 10.7). The reactions of DPNPIN with R-BI⊖ are strongly catalyzed by the micelles of CPyCl. Dephosphorylation of DPNPIN is accelerated by BI⊖ ion in 10 -2 M carbonate buffer(pH 10.7) of 4×10 -3 M CPyCl solution up to 100 times as compared with the reaction in carbonate buffer by no BI solution of 4×10 -3 M CPyCl. The value of pseudo first order rate constant(k m BI) of the reaction in CPyCl solution reached a maximum rate constant increasing micelle concentration. Such rate maxima are typical of micellar catalyzed bimolecular reactions. The reaction mediated by R-BI⊖ in micellar solutions are obviously slower than those by BI⊖, and the reaction rate were decreased with increase of lengths of alkyl groups. It seems due to steric effect of alkyl groups of R-BI⊖ in Stern layer of micellar solution. The surfactant reagent, cetylpyridinium chloride(CPyCl) , strongly catalyzes the reaction of diphenyl-4-nitrophenylphosphinate(DPNPIN) with alkylbenzimidazole (R-BI) and its anion(R-BI⊖) in carbonate buffer(pH 10.7). For example, 4×10 -3 M CPyCl in 1×10 -4 M BI solution increase the rate constant (kψ=1.0×10 -2 sec -1 ) of the dephosphorylation by a factor ca.14, when compared with reaction (kψ=7.3×10 -4 sec -1 ) in 1×10 -4 M BI solution(without CPyCl). And no CPyCl solution, in 1×10 -4 M BI solution increase the rate constant (kψ=7.3×10 -4 sec -1 ) of the dephosphorylation by a factor ca.36, when compared with reaction (kψ=2.0×10 -5 sec -1 ) in water solution(without BI). This predicts that the reactivities of R-BI⊖ in the micellar pseudophase are much smaller than that of BI⊖ . Due to the hydrophobicity and steric effect of alkyl group substituents, these groups would penetrate into the core of the micelle for stabilization by van der Waals interaction with long alkyl groups of CPyCl.

The phase transfer catalysis(PTC) reagent, ethyl tri-octyl ammonium bromide(ETABr), strongly catalyzes the reaction of p-nitrophenyl diphenyl phosphinate(p-NPDPIN) with benzimidazole(BI) and its anion(BI⊖). In ETABr solutions, the dephosphorylation reactions exhibit higher first order kinetics with respect to the nucleophile, BI, and ETABr, suggesting that reactions are occuring in small aggregates of the three species including the substrate(p-NPDPIN), whereas the reaction of p-NPDPIN with OH⊖ is not catalyzed by ETABr. This behavior for the drastic rate-enhancement of the dephosphorylation is referred as 'aggregation complex model' for reaction of hydrophobic organic phosphinates with benzimidazole(BI) in hydrophobic quarternary ammonium salt(ETABr) solutions.