Silver elimination effect by sulfuric acid for Ag pre-rteated activated carbon

오원춘 한국분석과학회 2006 분석과학 Vol.19 No.2

of adsorption, each isotherm shows a distinct knee band, which is characteristic of microporous adsorbents withcapillary condensation in micropores. In order to reveal the causes of the diferences in adsorption capacityand specific surface area after the samples were washed with various strengths of sulfuric acid, surfacemorphology and external pore structure were investigated by SEM. X-ray diffraction patterns indicated thatacid. The FT-IR spectra of silver-activated carbon samples show that the acid post-treatment was consequentlyassociated with the removal of silver with an increased surface functional group containing oxygen of theactivated carbon. The type and quality of oxygen groups are determined on the method proposed by Boehm.For the chemical composition microanalysis of silver-activated carbons transformed by post-treatment with

Synthesis and characterization of V–C60/TiO2 photocatalysts designed for degradation of methylene blue

오원춘,Feng-Jun Zhang,Ming-Liang Chen 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.2

C60/TiO2 andV–C60/TiO2composite photocatalysts were prepared with titanium(IV) n-butoxide (TNB) by a sol–gelmethod. Fullerenehad absorptive andsemiconducting properties,andvanadiumcouldenhance the photogenerated electron transfer. The V–C60/TiO2 composite shows a good photo-degradation activity. XRD patterns of the composites showed that the C60/TiO2 composite contained a mixture of anatase and rutile phase forms while the V–C60/TiO2 composite contained a typical single and clear anatase phase. The surface properties seen bySEMand FE-SEMpresent a characterization of the texture onC60/TiO2 andV–C60/TiO2composites and showeda homogenous composition in the particles for the titaniumsources used. The EDX spectra for the elemental identification showed the presence of C and Ti with strongV peaks for the V–C60/TiO2 composite. From the photocatalytic results, the excellent activity of the C60/TiO2 and V–C60/TiO2 composites for degradation of methylene blue under UV irradiation could be attributed to both the effects between photocatalysis of the supported TiO2 and charge transfer of the fullerene, and the introduction of vanadium to enhance the photogenerated electrons transfer.

Preparation of Fe-ACF/TiO2 Composites and their Photocatalytic Degradation of Waste Water

오원춘,배장순 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.11

In this study, we prepared Fe-activated carbon fiber(ACF)/TiO2 composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/TiO2 composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/TiO2 composites. The chemical composition of the Fe-ACF/TiO2 composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/TiO2 composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported TiO2, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF. In this study, we prepared Fe-activated carbon fiber(ACF)/TiO2 composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/TiO2 composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/TiO2 composites. The chemical composition of the Fe-ACF/TiO2 composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/TiO2 composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported TiO2, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF.

Preparation of Spherical Activated Carbon and Their Physicochemical Properties

오원춘,김종규,Ming-Liang Chen,Feng-Jun Zhang,Kan Zhang,김혁,Ze-Da Meng 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.6

In this study, we used coal based activated carbons as starting material and phenolic resin (PR) as a bonding agent to prepare spherical shaped activated carbons. The textural properties of SAC were characterized by BET surface area, XRD, SEM, iodine adsorption, strength intensity and pressure drop. According to the results, the spherical activated carbon prepared with activated carbon and PR at a ratio of 60:40 was found to have the best formation of spherical shape, which was found in sample SAC40. After activation, SAC40 has high BET surface area, iodine adsorption capability and strength value, and lowest pressure drop.

Properties of and Photocatalytic Activity of Pitch-binded ACF/TiO2 Composites

오원춘,정아람 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.3

Pitch-binded activated carbon fiber(ACF)/TiO2 composite photocatalysts were prepared by Carbon Tetra Chloride (CTC) solventmixing method with diferent mixing ratios of anatase to ACF. The result of the textural surface properties demonstrated thatthere is a slight increase in the Brunauer, Emmet and Teller (BET) surface area of composites with an increase of the amount o fACF. The surfaces structure morphologies of the composites were observed using an Scanning Electron Microscope (SEM). In theXRD patterns for all ACF/TiO2 composites, the diffraction peaks showed the formation of anatase crystallites. The EDX spectrashowed the presence of C, O and Si with strong Ti peaks. Most of these samples were richer in carbon and major Ti metal thanany other elements. From the photo-decomposition results, the excellent activity of the ACF/TiO2 composites between c/c0 formethylene blue and UV irradiation time could be attributed to both the effects of the photocatalysis of the supported TiO 2 andadsorptivity of activated carbon fiber and another carbon derived from pitch.

Characterization and photodegradation characteristics of organic dye for Pt–titania combined multi-walled carbon nanotube composite catalysts

오원춘,Feng-Jun Zhang,Ming-Liang Chen 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.2

Multi-walled carbon nanotubes (MWCNTs), titanium(IV) isopropoxide (TIP) and potassium hexachloroplatinate(IV) (K2PtCl6) were used for the preparation of Pt/MWCNT/TiO2 composites. The composites were comprehensively characterized by Brauer–Emett–Teller surface area, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and UV–vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation was tested using the conversion of methylene blue (MB) in aqueous solution. According to the results ofMBremoval experiment, it can be considered that the MB removal effect of the Pt/MWCNT/TiO2 composites is affected by two kinds of effects: adsorption effect by MWCNTs and photocatalytic effect by TiO2. Finally, the photocatalytic effect increases due to photo-induced-electron absorption effect by MWCNTs and electron trap effect by Pt metal.

Characterization and photonic properties for the Pt-fullerene/TiO2 composites derived from titanium (IV) n-butoxide and C60

오원춘,Weon-Bae Ko 한국공업화학회 2009 Journal of Industrial and Engineering Chemistry Vol.15 No.6

In this study, the structural variations, surface states, and mass transformations of fullerene [C60] derivatives were investigated through the preparation of Pt-decorated oxidized fullerene and a Ptfullerene/TiO2 composite and comparison to an oxidized fullerene [C60O]. These derivatives were synthesized with an improved oxidation method using m-chloroperbenzoic acid (MCPBA). Weak and strong peaks of metallic platinum and titanium dioxide, along with weak pristine fullerene [C60] peaks, were observed in the XRD patterns for the Pt-fullerene and Pt-fullerene/TiO2 composite. SEM micrographs for the metallic Pt-fullerene and Pt-fullerene/TiO2 composite indicated that practically all the platinum and titanium dioxide that were introduced were located on the carbon cages and consequently, were dispersed into very small crystallites with growth of platinum metals and titanium dioxide. The EDX spectra of Pt-fullerene and Pt-fullerene/TiO2 composite showed the presence of C, O, and Pt, with strong Ti peaks. From the MALDI-TOF mass spectra, the differences in the spectra for the three kinds of fullerene derivatives were due to oxidation including chemical bonding and interposing of metallic platinum and titanium dioxide in the fullerene [C60] molecules. And, absorption property demonstrated by UV–vis diffuse reflectance method. From the photocatalytic results, the excellent activity of the Pt-fullerene/TiO2 composites for organic dye and UV irradiation time could be attributed to the synergetic effects between photocatalysis of the supported TiO2 and absorptivity of the platinum and fullerene.

Electro-catalytic Removal of Water Pollutants by Silver-ACF from Piggery Waste

오원춘,Tong-So Park 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.5

Effect of Acid Pretreatment on the Metal Loading of Activated Carbon

오원춘 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.1

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.