• 제목/요약/키워드: Titanium dioxide($TiO_2$) nanorod

검색결과 3건 처리시간 0.017초

FTO 기판위 TiO2 나노로드의 시드박막층 (Seed Layers in TiO2 Nanorods on FTO)

  • 김현;양비룡
    • 한국세라믹학회지
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    • 제52권1호
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    • pp.9-12
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    • 2015
  • Nano-structured electrodes were fabricated to develop efficient photoelectrochemical conversion systems for the synthesis of hydrogen from water and hydrocarbon fuels from $CO_2$. In this work, we compared the photoactivity of rutile $TiO_2$ nanorods grown on FTO and SEED/FTO by a hydrothermal method. An analysis of the microstructures showed that the density of nanorod/SEED/FTO samples, which showed only the (002) peak in their x-ray diffraction patterns, was two times higher than that of a nanorod/FTO sample. The photocurrent density of nanorod/SEED/FTO samples was increased by as much as 40% of the photocurrent density of the nanorod/FTO sample due to the increased specific density of the nanorods. However, the transient time for a recombination of photogenerated electrons and holes was 20 times faster in the nanorod/SEED/FTO. The seed layers are discussed as possible recombination sites.

Comparison of Luminescence Properties of Electrochemical Luminescence Cells for Various Electrode Materials and Structures

  • Pooyodying, Pattarapon;Ok, Jung-Woo;Sung, Youl-Moon
    • Journal of Electrical Engineering and Technology
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    • 제12권4호
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    • pp.1605-1610
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    • 2017
  • The electrochemical luminescence (ECL) device was investigated, which has similar structure to the dye-sensitized solar cell. The structure of the ECL cell in this experiment reliably induces a large amount of the oxidation around electrodes. The band gap of the ECL electrode is of 3.0 - 3.2 eV. Titanium dioxide ($TiO_2$) nanoparticle has following properties: a band gap of 3.4 eV, a low-priced material, and 002 preferred orientation (Z-axis). Zinc Oxide (ZnO) nanorod is easy to grow in a vertical direction. In this paper, in order to determine material suitable for the ECL device, the properties of various materials for electrodes of ECL devices such as ZnO nanorod (ZnO-NR) and $TiO_2$ nanoparticle ($TiO_2-NP$) were compared. The threshold voltage of the light emission of the ZnO-NR was 2.0 V which is lower than 2.5 V of $TiO_2-NP$. In the other hand, the luminance of $TiO_2-NP$ was $44.66cd/m^2$ and was higher than that of $34cd/m^2$ of ZnO-NR at the same applied voltage of 4 V. Based on the experimental results, we could conclude that $TiO_2-NP$ is a more suitable electrode material in ECL device than the ZnO-NR.

Photocurrent Properties of TiO2 Nanorods Grown on FTO by Hydrothermal Method

  • Kim, Hyun;Yang, Bee Lyong
    • 한국세라믹학회지
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    • 제52권6호
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    • pp.531-534
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    • 2015
  • In this work, we undertake a comparative study of the crystallographic microstructures and photo-catalytic properties of rutile $TiO_2$ nanorods grown on FTO facing up and down by a hydrothermal method. An analysis of the fine structures showed that $TiO_2$ nanorods grown on FTO facing up were mixed with sea urchin and microsphere. These structures induced a vertical orientation of the nanorods on FTO. The saturated photocurrent densities of the $TiO_2$ nanorods grown both up and down were $1.5mA/cm^2$ in the former case, the IPCE was increased to 10% at 300~350 nm. The onset potential (${\fallingdotseq}$ flat band potential) of the nanorods grown on FTO facing up is negatively shifted to a value of -0.31 V. This is caused by an increase in the surface state, in this case the number of oxygen vacancies, and by the formation of $Ti^{3+}$. Therefore, the FTO facing direction is considered as a critical factor during the hydrothermal reaction for $TiO_2$ growth so as to develop an efficient photo-catalytic system.