Development of Visible Light Sensitive TiO2 Photocatalysts and Their Sensitization Using Fe3+ Ions
Development of Visible Light Sensitive TiO2 Photocatalysts and Their Sensitization Using Fe3+ Ions
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DOI：
10.1627/jpi.49.168
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发表时间：
2006
影响因子：
1
通讯作者：
T. Ohno
中科院分区：
文献类型：
--
作者：
T. Ohno
二氧化钛光催化剂是光降解水和空气中污染物的很有前途的基质，但仅在紫外光下才显示出光催化活性。为了利用更大范围的入射波长，如太阳光，开发可见光下活性的光催化剂是非常重要的。用S(S 4+)取代部分晶格钛原子或N取代部分晶格O原子制备了锐钛矿型化学修饰二氧化钛光催化剂。这些催化剂对可见光有很强的吸收，对水溶液中异丙醇的降解和金刚烷的部分氧化表现出较高的活性。X射线光电子能谱分析表明，二氧化钛颗粒中的S和N原子的氧化态分别为S 4+和N3-。在较宽的入射波长范围(包括紫外光和可见光)下，吸附Fe3+离子的S掺杂或N掺杂TiO2光催化剂对异丙醇的氧化活性明显高于未掺杂Fe3+的S或N掺杂TiO2光催化剂.光催化活性在S掺杂的TiO2光催化剂上吸附了0.90wt%的Fe3+，在N掺杂的TiO2光催化剂上吸附了0.36wt%的Fe3+。此外，对吸附了Fe3+离子的S掺杂或氮掺杂的TiO2光催化剂进行NaBH4还原和空气氧化处理后，光催化活性进一步提高。在这种情况下，Fe3+在S掺杂和N掺杂的TiO2光催化剂表面的最佳含量分别为2.81wt%和0.88wt%。
Titanium dioxide photocatalysts are promising substrates for photodegradation of pollutants in water and air, but show photocatalytic activities only under UV light. To utilize a wider range of incident wavelengths such as solar light, development of photocatalysts active under visible light is very important. Chemically modified titanium dioxide photocatalysts were prepared containing anatase phase with S (S 4+ ) substituted for some lattice Ti atoms or N substituted for some lattice O atoms. These catalysts showed strong absorption of visible light and high activities for degradation of 2-propanol in aqueous solution and partial oxidation of adamantane under irradiation at wavelengths longer than 440 nm. The oxidation states of the S and N atoms incorporated into the TiO 2 particles were determined to be mainly S 4+ and N 3- from XPS spectra, respectively. The photocatalytic activities of S- or N-doped TiO 2 photocatalysts with adsorbed Fe 3+ ions were markedly improved for oxidation of 2-propanol compared to those of S- or N-doped TiO 2 without Fe 3+ ions under a wide range of incident wavelengths, including UV light and visible light. The photocatalytic activity reached maximum with 0.90 wt% Fe 3+ ions adsorbed on S-doped TiO 2 , and 0.36 wt% Fe 3+ ions on N-doped TiO 2 . Furthermore, redox treatment of S- or N-doped TiO 2 photocatalysts with adsorbed Fe 3+ ions by reduction with NaBH 4 followed by air oxidation resulted in further improvements in photocatalytic activities. In this case, the optimum amounts of Fe 3+ were 2.81 and 0.88 wt% on the surfaces of S- and N-doped TiO 2 photocatalysts, respectively.