高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

δ-MnO2对TiO2光催化降解甲基橙的抑制作用

李顺军1, 马子川1,2, 丁克强1, 刘敬泽2   

    1. 河北师范大学化学与材料科学学院,
    2. 生命科学学院, 石家庄 050016
  • 收稿日期:2007-08-08 修回日期:1900-01-01 出版日期:2007-12-10 发布日期:2007-12-10
  • 通讯作者: 马子川

Inhibition Effect of δ-MnO2 on TiO2 Photocatalytic Degradation of Methyl Orange

LI Shun-Jun1, MA Zi-Chuan1,2*, DING Ke-Qiang1, LIU Jing-Ze2*   

    1. College of Chemistry and Material Sciences,
    2. College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
  • Received:2007-08-08 Revised:1900-01-01 Online:2007-12-10 Published:2007-12-10
  • Contact: MA Zi-Chuan

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摘要： 采用动力学方法研究了在水悬浮液中δ-MnO2颗粒物对P-25 TiO2光催化降解甲基橙活性的影响, 并利用紫外-可见漫反射光谱(DRS)和光致发光光谱(PL)对受δ-MnO2污染前后的TiO2样品进行了表征. 动力学研究结果表明, 在3种不同初始pH值条件下, δ-MnO2对TiO2光催化剂都具有明显的致毒效应, 共存δ-MnO2的浓度越大, 致毒效应越明显. 表征结果表明, 由于δ-MnO2 与TiO2之间的界面接触, 使得TiO2吸收带边蓝移, 紫外光区的吸收强度降低, 光致发光信号(PL)明显减弱. 因此, δ-MnO2导致TiO2的禁带宽度增大, 光利用率降低, 并且是光生电子与空穴的复合中心.

关键词: TiO2, δ-MnO2, 失活, 光催化, 甲基橙

Abstract: The influences of δ-MnO2 particles on the photocatalytic activity of P-25 TiO2 were investigated with kinetical method through the photocatalytic degradation of methyl orange. The TiO2 photocatalyst, before and after being contaminated by δ-MnO2, was characterized with UV-visible diffuse reflectance spectroscopy(UV-Vis DRS) and photoluminescence(PL). The dynamics results show the distinct existence of poisoning effect of δ-MnO2 on TiO2 photocatalysis at different initial pH values. The higher the concentration of the δ-MnO2, the more evident the poisoning effect. The characterizations indicate that the absorption band edge of TiO2 is blue-shifted and the intensity is decreased, and the intensity of PL signals of TiO2 is suppressed due to the contact between δ-MnO2 and TiO2. Therefore, the presence of δ-MnO2 increases the band gap and causes the decrease of UV absorption of TiO2, and δ-MnO2 can also act as a recombination centers of photoinduced electron-hole. The effects of δ-MnO2 particles in environment on the stability of TiO2 photocatalyst were revealed.

Key words: TiO2, δ-MnO2, Deactivation, Photocatalysis, Methyl orange

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