二氧化钛与针铁矿复合光催化材料的制备与光催化性能

Preparation and photocatalytic activity of rutile TiO_2 and goethite composite photocatalysts

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.

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. 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.