Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
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A study on reactive chlorine species generation enhanced by heterojunction structures on surface of IrO2-based anodes for water treatment

IrO2 기반 수처리용 산화 전극의 표면 이종 접합 구성에 따른 활성 염소종 발생 증진 특성 연구

  • Hong, Sukhwa (Division of Environmental Science and Engineering, Pohang University of Science and Technology) ;
  • Cho, Kangwoo (Division of Environmental Science and Engineering, Pohang University of Science and Technology)
  • 홍석화 (포항공과대학교 환경공학부) ;
  • 조강우 (포항공과대학교 환경공학부)
  • Received : 2018.06.22
  • Accepted : 2018.07.31
  • Published : 2018.08.15
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Abstract

This study interrogated multi-layer heterojunction anodes were interrogated for potential applications to water treatment. The multi-layer anodes with outer layers of $SnO_2/Bi_2O_3$ and/or $TiO_2/Bi_2O_3$ onto $IrO_2/Ta_2O_5$ electrodes were prepared by thermal decomposition and characterized in terms of reactive chlorine species (RCS) generation in 50 mM NaCl solutions. The $IrO_2/Ta_2O_5$ layer on Ti substrate (Anode 1) primarily served as an electron shuttle. The current efficiency (CE) and energy efficiency (EE) for RCS generation were significantly enhanced by the further coating of $SnO_2/Bi_2O_3$ (Anode 2) and $TiO_2/Bi_2O_3$ (Anode 3) layers onto the Anode 1, despite moderate losses in electrical conductivity and active surface area. The CE of the Anode 3 was found to show the highest RCS generation rate, whereas the multi-junction architecture (Anode 4, sequential coating of $IrO_2/Ta_2O_5$, $SnO_2/Bi_2O_3$, and $TiO_2/Bi_2O_3$) showed marginal improvement. The microscopic observations indicated that the outer $TiO_2/Bi_2O_3$ could form a crack-free layer by an incorporation of anatase $TiO_2$ particles, potentially increasing the service life of the anode. The results of this study are expected to broaden the usage of dimensionally stable anodes in water treatment with an enhanced RCS generation and lifetime.

Keywords

References

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