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Preparation of $N-TiO_2$ Photocatalysts and Activity Test

$N-TiO_2$ 광촉매의 제조와 광촉매 활성 검토

  • Kang, Young-Gu (Department of Chemical Engineering, Myongji University) ;
  • Shin, Ki-Seok (Department of Chemical Engineering, Myongji University) ;
  • Ahn, Sung-Hwan (Department of Chemical Engineering, Myongji University) ;
  • Hahm, Hyun-Sik (Department of Chemical Engineering, Myongji University)
  • 강영구 (명지대학교 공과대학 화학공학과) ;
  • 신기석 (명지대학교 공과대학 화학공학과) ;
  • 안성환 (명지대학교 공과대학 화학공학과) ;
  • 함현식 (명지대학교 공과대학 화학공학과)
  • Received : 2012.08.31
  • Accepted : 2012.09.21
  • Published : 2012.09.30

Abstract

Visible-light-responding photocatalysts, $N-TiO_2$, were prepared by nitrogen doping onto $TiO_2$. The crystalline structure and morphology, doping state of the prepared photocatalysts were characterized by XRD, FE-SEM, and XPS. The activity of the prepared photocatalysts was examined by the decomposition of methyleneblue. The prepared catalysts were anatase type and the crystallinity was increased with pH. The particle sizes of the prepared catalysts were 5.42, 5.99, 7.58 nm at pH 2.2, 4.7, 9.0, respectively. The particle sizes of the prepared catalysts were slightly increased with pH. The activity of the photocatalysts was directly proportional to the crystallinity of the catalysts. $N-TiO_2$ prepared by nitrogen doping onto $TiO_2$ showed activity under visible light. The doped nitrogen was located not in the lattice but on the surface.

가시광선에 감응하는 광촉매를 제조하기 위하여 $TiO_2$에 질소(N)를 도핑하여 $N-TiO_2$를 제조하였다. 제조한 광촉매의 결정성, 입자 형상 및 도핑 상태는 XRD, FE-SEM 및 XPS를 이용하여 조사하였다. 제조한 광촉매의 활성 평가는 메틸렌블루의 광분해로 조사하였다. 제조한 광촉매는 anatase type이었으며, pH가 높을수록 결정화도가 향상되었다. 제조한 광촉매의 입자 크기는 pH 2.0에서 5.42 nm, pH 4.7에서 5.99 nm, pH 9.0에서 7.58 nm로, 입자 크기는 pH가 증가 할수록 약간씩 증가하였다. 광촉매의 활성은 결정화도에 비례하였다. $TiO_2$에 N를 도핑하여 제조한 $N-TiO_2$가 가시광선 하에서도 활성을 나타냈다. $TiO_2$에 도핑한 N는 격자 속에 존재하는 것이 아니라 표면에 존재하였다.

Keywords

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