Photonic Aspects of MB Degradation on Fe-carbon/TiO2 Composites under UV Light Irradiation

Kan Zhang,Ze-Da Meng,오원춘 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.5

Fe-carbon/TiO2 composites were prepared by a sol-gel method using AC, ACF, CNT and C60 as carbon precursors and were characterized by means of BET surface area, X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The activity of the prepared photocatalysts was investigated by degradation reaction of methylene blue (MB) irradiated with UV lamp. Effects of different carbon sources and irradiation time on photocatalytic activity were also investigated. The results showed that the photocatalytic activity of the Fe-carbon/TiO2 composites was much higher than that of pristine TiO2 and Fe/TiO2 composites. The prominent photocatalytic activity of Fecarbon/TiO2 composites could be attributed to both the effects of photo-adsorption and electron transfer by carbon substrate. In addition, the higher photocatalytic activity of Fe-carbon/TiO2 composites can be compared with that of carbon/TiO2 and Fe /TiO2 composites due to cooperative effects between Fe and carbon.

Fabrication of Fe-ACF/TiO₂ composites and their photonic activity for organic dye

Kan Zhang(장간),Ze-Da Meng(맹칙달),Weon-Bae Ko(고원배),Won-Chun Oh(오원춘) 한국분석과학회 2009 분석과학 Vol.22 No.3

Photodecomposition of Different Organic Dyes Using Fe-CNT/TiO2 Composites under UV and Visible Light

Kan Zhang,Ze-Da Meng,오원춘 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.2

The Fe-treated CNT/TiO2 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/TiO2 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 Fe3+ 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 TiO2 under visible light irradiation. The composites of Fe-CNT/TiO2 photocatalysts synthesized by a sol-gel method were characterized by BET, TEM, SEM, XRD and EDX.

Characterization of Fe-ACF/TiO₂ composite and photocatalytic activity for MB Solution under visible light

Kan Zhang(장간),Ze-Da Meng(맹칙달),Won-Chun Oh(오원춘) 한국분석과학회 2010 분석과학 Vol.23 No.3

Preparation of Different Fe Containing TiO₂ Photocatalysts and Comparison of Their Photocatalytic Activity

Meng, Ze-Da,Zhang, Kan,Oh, Won-Chun Materials Research Society of Korea 2010 한국재료학회지 Vol.20 No.4

In this paper, Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ composite photocatalysts were prepared with titanium (IV) n-butoxide (TNB) by a sol-gel method. $TiO_2$, Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ were characterized by scanning electron microscopy (SEM), Transmission electron microscope (TEM), specific surface area (BET), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDX). The photocatalytic activities were evaluated by the photocatalytic oxidation of methylene blue (MB) solution. XRD patterns of the composites showed that the photocatalyst composite contained a typical single and clear anatase phase. The surface properties shown by SEM presented a characterization of the texture on Fe-fullerene/$TiO_2$ composites and showed a homogenous composition in the particles for the titanium sources used. The EDX spectra for the elemental identification showed the presence of O, C and Ti elements. Moreover, peaks of the Fe element were observed in the Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ composites. The degradation of MB solution by UV-light irradiation in the presence of photocatalyst compounds was investigated in complete darkness. The degradation of MB concentration in aqueous solution occurred via three kinds of physical phenomena: quantum efficiency of the fullerene; organo-metallic reaction of the Fe compound; and decomposition of $TiO_2$. The degradation rate of the methylene blue solution increased when using Fe-fullerene/$TiO_2$ compounds.

A Novel Synthesis and Photonic Effect of Fe-CNT/TiO₂ Composites by Controlling of Carbon Nanotube Amounts

Zhang, Kan,Meng, Ze-Da,Oh, Won-Chun Materials Research Society of Korea 2010 한국재료학회지 Vol.20 No.3

Titanium dioxide ($TiO_2$) particles deposited on different quantitative Fe-treated carbon nanotube (CNT) composites with high photocatalytic activity of visible light were prepared by a modified sol-gel method using TNB as a titanium source. The composites were characterized by BET, XRD, SEM, TEM and EDX, which showed that the BET surface area was related to the adsorption capacity for each composite. From TEM images, surface and structural characterization of for the CNT surface had been carried out. The XRD results showed that the Fe-ACF/$TiO_2$ composite mostly contained an anatase structure with a Fe-mediated compound. EDX results showed the presence of C, O, and Ti with Fe peaks in the Fe-CNT/$TiO_2$ composites. The photocatalytic activity of the composites was examined by degradation of methylene blue (MB) in aqueous solution under visible light, which was found to depend on the amount of CNT. The highest photocatalytic activity among the different composites was related to the optimal content of CNT in the Fe-CNT/$TiO_2$ composites. In particular, the photocatalytic activity of the Fe-CNT/$TiO_2$ composites under visible light was better than that of the CNT/$TiO_2$ composites due to the introduction of Fe particles.

Photodegradation of MB on Fe/CNT-TiO₂ Composite Photocatalysts Under Visible Light

Zhang, Kan,Meng, Ze-Da,Choi, Jong-Geun,Oh, Won-Chun Materials Research Society of Korea 2010 한국재료학회지 Vol.20 No.5

The composite photocatalysts of a Fe-modified carbon nanotube (CNT)-$TiO_2$ were synthesized by a two-step sol-gel method at high temperature. Its chemical composition and surface properties were investigated by BET surface area, scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray diffraction (XRD) and ultraviolet-visible (UV-Vis) spectroscopy. The results showed that the BET surface area was improved by modification of Fe, which was related to the adsorption capacity for each composite. Interesting thin layer aggregates of nanosized $TiO_2$ were observed from TEM images, probably stabilized by the presence of CNT, and the surface and structural characterization of the samples was carried out. The XRD results showed that the Fe/CNT-$TiO_2$ composites contained a mix of anatase and rutile forms of $TiO_2$ particles when the precursor is $TiOSO_4{\cdot}xH_2O$ (TOS). An excellent photocatalytic activity of Fe/CNT-$TiO_2$ was obtained for the degradation of methylene blue (MB) under visible light irradiation. It was considered that Fe cation could be doped into the matrix of $TiO_2$, which could hinder the recombination rate of the excited electrons/holes. The photocatalytic activity of the composites was also found to depend on the presence of CNT. The synergistic effects among the Fe, CNT and $TiO_2$ components were responsible for improving the visible light photocatalytic activity.

Fe-ACF/TiO2 복합체의 특성과 MB용액의 분해에서 포토-펜톤 효과

장간 ( Kan Zhang ),맹칙달 ( Ze Da Meng ),고원배 ( Weon Bae Ko ),오원춘 ( Won Chun Oh ) 한국고무학회 2009 엘라스토머 및 콤포지트 Vol.44 No.3

본 논문에서 Fe-활성탄소 섬유(ACF)/TiO2 복합체 광촉매를 졸-겔 방법에 의하여 제조하였다. 합성된 광촉매는 UV조사하에서 MB용액의 광분해에 사용되었다. BET 데이터는 Fe와 Ti의 여러 가지 농도를 가지고 처리된 ACF의 표면에서 흡착 특성을 보여준다. SEM 사진에서 보여지는 것처럼, 철 혼합물과 TiO2는 ACF 표면에 활착되어 있음을 나타내었다. X선 분말 회절법으로부터 얻어진 결과는 복합체로부터 FeO+TiO2, Anatase 및 Rutile 구조의 결정상을 나타내었다. 원소분석을 위한 EDX spectra는 Fe와 함께 C, O, Ti의 peak들이 존재함을 나타내었다. MB분해에 대한 활성은 TiO2의 광분해와 Fe의 photo-Fenton 효과로 인해 전자/hole쌍 반응으로부터 파생된 ·OH 라디칼들에 의한 것으로 여겨진다. In this paper, the Fe-activated carbon fiber (ACF)/TiO2 composite catalysts were prepared by a sol-gel method. The synthesized photocatalysts were used for the photo degradation of Methylene blue solution under UV light. From Brunauer-Emmett-Teller measurements (BET) data, it was shown the blocking of the micropores on the surface of ACF by treatment of Fe and Ti compound. As shown in SEM images, the ferric compounds and titanium dioxides were fixed onto the ACF surfaces. The result of X-ray powder diffraction showed that the crystal phase contained a mixing anatase and rutile structure and the `FeO+TiO2` from the composites. The EDX spectra for the elemental analysis showed the presence of C, O, and Ti with Fe peaks. Degradation activity of MB could be attributed to ·OH radicals derived from electron/hole pair`s reactions due to photolysis of TiO2 and photo-Fenton effect of Fe.

Photonic Aspects of MB Degradation on Fe-carbon/TiO₂ Composites under UV Light Irradiation

Zhang, Kan,Meng, Ze-Da,Oh, Won-Chun The Korean Ceramic Society 2010 한국세라믹학회지 Vol.47 No.5

Fe-carbon/$TiO_2$ composites were prepared by a sol-gel method using AC, ACF, CNT and $C_{60}$ as carbon precursors and were characterized by means of BET surface area, X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The activity of the prepared photocatalysts was investigated by degradation reaction of methylene blue (MB) irradiated with UV lamp. Effects of different carbon sources and irradiation time on photocatalytic activity were also investigated. The results showed that the photocatalytic activity of the Fe-carbon/$TiO_2$ composites was much higher than that of pristine $TiO_2$ and Fe/$TiO_2$ composites. The prominent photocatalytic activity of Fecarbon/$TiO_2$ composites could be attributed to both the effects of photo-adsorption and electron transfer by carbon substrate. In addition, the higher photocatalytic activity of Fe-carbon/$TiO_2$ composites can be compared with that of carbon/$TiO_2$ and Fe /$TiO_2$ composites due to cooperative effects between Fe and carbon.

Photodecomposition of Different Organic Dyes Using Fe-CNT/TiO₂ Composites under UV and Visible Light

Zhang, Kan,Meng, Ze-Da,Oh, Won-Chun The Korean Ceramic Society 2010 한국세라믹학회지 Vol.47 No.2

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.