二氧化钛与针铁矿复合光催化材料的制备与光催化性能

以四氯化钛为钛源,针铁矿(α-FeOOH)为载体,采用水解沉淀法制备了金红石相二氧化钛(Ti₂O)与α-FeOOH的复合光催化材料,并采用X射线衍射、扫描电子显微镜、透射电子显微镜、X射线能量散射谱和X射线光电子能谱对样品进行了表征.结果表明,低温下,金红石相Ti₂O包覆于α-FeOOH表面,并形成复合结构;较高温下,铁离子进入金红石相Ti₂O晶格,并形成铁掺杂金红石相Ti₂O纳米管;中温下,样品兼有复合和掺杂两者特征.在室温下以甲基橙为降解对象,采用钨灯+氘灯(波长200~800nm)为光源,对样品的光催化活性进行了测试.结果表明,样品对甲基橙的光催化降解效果良好;与纯α-FeOOH和金红石相Ti₂O相比,不同结构样品的光催化活性均有所提高,其中,复合兼掺杂型样品的光催化活性最高.由此可见,与α-FeOOH复合和铁掺杂是提高Ti₂O光催化活性的有效途径.

Preparation and photocatalytic activity of rutile TiO2 and goethitecomposite photocatalysts

Rutile TiO₂ and goethite (α-FeOOH) composite photocatalysts were fabricated by hydrolysis and precipitation using titanium tetrachloride as a precursor and α-FeOOH as a support. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The results show that at lower temperature, rutile TiO₂ particles coat on the surface of α-FeOOH particles to form rutile TiO₂-α-FeOOH composite photocatalyst. At higher temperature, iron ions are doped into the rutile TiO₂ lattice to form iron-doped rutile TiO₂ tubes; at medium temperature, the sample is a mixture with both composite and iron-doped structures. The photocatalytic activity of the samples is estimated by their ability to degrade methyl orange under irradiation with ultraviolet-visible light (200-800 nm) at ambient temperature. The photocatalytic activities of the samples are improved compared with that of pure rutile TiO₂ and α-FeOOH. The sample containing a mixture of composite and iron-doped structures shows the highest photocatalytic activity of that investigated. As a result, the photocatalytic activity of Ti₂O could be improved effectively by combining with α-FeOOH or doping iron.