인산을 전처리한 활성탄소섬유에 칼륨 처리효과

오원춘,배장순 한국분석과학회 2005 분석과학 Vol.18 No.4

Properties of Metal Supported Porous Carbon and Bactericidal Effects

오원춘 한국공업화학회 2003 Journal of Industrial and Engineering Chemistry Vol.9 No.2

Surface Properties of Metal-ACFs Transformed through Acid Post-treatment

오원춘 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.6

Preparation of Fullerene/TiO2 Composite and Its Photocatalytic Effect

오원춘,Ah-Reum Jung,고원배 한국공업화학회 2007 Journal of Industrial and Engineering Chemistry Vol.13 No.7

A Fullerene/TiO2 composite photocatalyst was prepared with titanium (IV) n-butoxide (TNB) by using a MCPBA oxidation method. Since fullerene has absorptive and semiconducting properties, the fullerene/TiO2 composite revealed a sound photo-degradation activity. From the XRD data, a strong carbon peak of fullurene graphene remained and anatase and rutile peaks were observed in the X-ray diffraction patterns for the fullerene/TiO2 composite. The surface properties seen by SEM present a characterization of the texture on the fullerene/TiO2 composite and homogenous compositions in the particles for the titanium sources that were used. For the elemental identification, the EDX spectra showed the presence of C and O with strong Ti peaks. From the MALDI-TOF mass spectrum of the fullerene/TiO2 composite, the observation of the peak due to titanium trace appeared at 878.7 and 894.8 m/z. This is also consistent with the elemental compositions of C60(TiO2)2 and C60O(TiO2)2. From the photocatalytic results, the excellent activity of the fullerene/TiO2 composites for organic dye and UV irradiation time could be attributed to both the effects between the photocatalysis of the supported TiO2 and the absorptivity of the fullerene.

Photocatalytic effect of TiO2-coated CaLa2(MoO4)4 and CaLa2(MoO4)4:Er/Yb nano core–shells and upconversion photoluminescence properties of CaLa2(MoO4)4:Er/Yb phosphors

오원춘,임창성,Shu Ye,박정규,강석현 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.32 No.-

TiO2-coated CaLa2(MoO4)4 and CaLa2(MoO4)4:Er/Yb nano core–shells were successfully synthesizedusing two-step procedures of the microwave sol–gel and ultrasonic methods. Well-crystallized nanocore–shells showed a fine and homogeneous morphology with particle sizes of 10–20 nm. Thedegradation efficiency for TiO2-coated CaLa2(MoO4)4 and CaLa1.7(MoO4)4:Er0.1Yb0.2 under visible lightresulted in the order as 10 > 15 > 5 wt%. Under excitation at 980 nm, the upconversion intensities ofCaLa1.7(MoO4)4:Er0.1Yb0.2 and CaLa1.5(MoO4)4:Er0.05Yb0.45 particles exhibited a strong 525 nm and aweak 550 nm emission bands in the green region. The CIE diagram showed a good match with yellowishgreen emissions.

Microstructures and photonic effects of titania dispersed inside/outside carbon nanotube composites derived from different titanium alkoxide precursors

오원춘,Feng-Jun Zhang,임창성,Ming-Liang Chen 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.4

The comparative microstructures and photonic effects of CNT/TiO2 composites which were derived from pre-oxidized carbon nanotubes and different titanium alkoxide precursors (titanium (IV) n-butoxide (TNB), titanium(IV) isopropoxide (TIP) and titanium(IV) propoxide (TPP)) by a sol-gel method. The composites were characterized by theirBrauer-Emett-Teller surface areas, transmission electron microscopy, X-ray diffraction, and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation was tested using methylene blue (MB) in an aqueous solution. The CNT/TiO2composites derived from the TIP precursor only existed in an anatase state with a very strong intensity, while the CNT/TiO2composites derived from TIP and TPP precursors included a mixed structure of anatase and rutile. The TiO2 particles were embedded into the tubes of CNTs for the CNT/TiO2 composites derived from the precursors with TNB and TIP, while for the CNT/TiO2 composites from TPP the TiO2 particles were only distributed outside the surfaces of the CNTs and partially aggregated. The CNT/TiO2 composites derived from TPP have a higher degradation effect on the MB solution more than that of TNB and TIP as titania precursors. A mechanism of TiO2 particles dispersing inside or outside of the CNT is proposed.

Metal elimination effect by sulfuric acid for Ag and Cu pre-treated activated carbon

오원춘,임창성 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.2

From the results of adsorption, each isotherm shows a distinct knee band, which is characteristic of microporous adsorbents with capillary condensation in micropores. In order to reveal the causes of the differences in adsorption capacity and specific surface area after the samples were washed with various strengths of sulfuric acid, surface morphology and pore structure were investigated by SEM. X-ray diffraction patterns indicated that activated carbon containing metal species show better performance for metal and metal compound removal by post-treatment with acid. The FT-IR spectra of metal-activated carbon samples show that the acid post-treatment was consequently associated with the removal of metals with an increased surface functional group containing oxygen of the activated carbon. The type and quality of oxygen groups are determined on the method proposed by Boehm. For the chemical composition microanalysis of metal-activated carbons transformed by post-treatment with sulfuric acid, samples were analyzed by EDX.

Physical properties of KPACFs and their pH dependence on their T-N and T-P removal

오원춘,Chong-Sung Park,Chang-Sung Lim 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

In this study, the characterizations of powdered activated carbon fiber treated with potassium (KPACFs) systems by nitrogen adsorption, SEM-EDX, UV/VIS, Boehm titration and removal efficiencies of pollutants by variation of pH are presented. From the adsorption and surface analysis, it is shown that the ACF samples prepared by treatment with aqueous solutions containing potassium ions or salts have a more heterogeneous micropore structure. SEM images and EDX spectra show a homogeneous distribution of potassium salts on the large body fiber surface and the presence of C, O and P. Quantitative analyses of surface species including oxygen groups are determined by FT-IR and Boehm’s titration methods. Finally, the color, total nitrogen (TN) and total phosphate (T-P) removal performance of piggery waste dispersed with KPACFs is investigated and these results are acceptable for the final disposal of the treated effluent depending on pH. In this study, the characterizations of powdered activated carbon fiber treated with potassium (KPACFs) systems by nitrogen adsorption, SEM-EDX, UV/VIS, Boehm titration and removal efficiencies of pollutants by variation of pH are presented. From the adsorption and surface analysis, it is shown that the ACF samples prepared by treatment with aqueous solutions containing potassium ions or salts have a more heterogeneous micropore structure. SEM images and EDX spectra show a homogeneous distribution of potassium salts on the large body fiber surface and the presence of C, O and P. Quantitative analyses of surface species including oxygen groups are determined by FT-IR and Boehm’s titration methods. Finally, the color, total nitrogen (TN) and total phosphate (T-P) removal performance of piggery waste dispersed with KPACFs is investigated and these results are acceptable for the final disposal of the treated effluent depending on pH.

Formation of TiO2 composites on activated carbon modified by nitric acid and their photocatalytic activity

오원춘,Ming-Liang Chen 한양대학교 세라믹연구소 2007 Journal of Ceramic Processing Research Vol.8 No.5

We have studied a method for the preparation of carbon/TiO2 composites involving the penetration of titanium n-butoxide (TNB) solution into activated carbon. The study has focused on the characterization of the TiO2 obtained in the porous carbon and how increased surface functional groups were created by the acid treatment. The conversion of TNB to TiO2 during the heat treatment must be important for the preparation of carbon/TiO2 composites. From the surface textural properties, both the BET surface area and the total pore volume decreased with the distribution of TiO2 on the activated carbon surfaces after the acid treatment. According to the results of SEM micrographs, titanium complex particles were regularly distributed on the carbon. Also some large clusters were found when the amount of acid treatment was increased. The changes in XRD patterns show typical anatase type on carbon/TiO2 composites prepared with activated carbon modified by nitric acid. The EDX results of carbon/TiO2 composites show the presence of C, O and S with strong Ti peaks. Observation of the absorption bands for the FT-IR spectra shows that the changes for the carbon/TiO2 composite prepared with activated carbon modified by nitric acid are mainly due to the formation of functional groups. Finally, the excellent photocatalytic activity of carbon/TiO2 composites between relative concentration (c/co) of MB and UV irradiation time could be attributed to both effects between photocatalysis of the formation of titania complexes and the adsorptivity of the activated carbon.

The preparation and characterization of a silver-containing fullerenes [C60]

오원춘,Ah-Reum Jung,고원배 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.1

In this study, we present the preparation and characterization of some Ag-containing fullerenes [C60]. From the XRD data, weak peaks of silver with pristine fullerene [C60] peaks were observed in the X-ray diffraction patterns for the fullerene [C60] treated with silver sequentially after oxidation. SEM and TEM micrographs for the Ag-containing fullerenes [C60] indicated that practically all the Ag atoms introduced are located onto the carbon edges or inside pores and consequently, it is dispersed into very small crystallites with the growth of Ag metals. From the Maldi-TOF-Mass spectra, the differences in the spectra recorded on three kinds of fullerene [C60] are due to the oxidation including chemical bonding and interposing of metallic silver in the C60 molecules. The FT-IR spectra gave additional information on functional components on the surface of silvercontaining fullerene [C60]. The EDX spectrum of silver-containing fullerene [C60] showed the presence of C and O with strong Ag peaks.