Jingchang ZHANG
,
Qing LI
,
Weiliang CAO
材料科学技术（英文）
A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%~30.1%) were prepared from TiCl4 and SnCl4•5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination technology. Characterizations with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed that, in addition to anatase type TiO2, a new active phase (Ti, Sn)O2 (with particle size of 2.0~4.3 nm) formed, and there were no SnO2 crystals observed in the range of the doping concentration studied. Photo-catalytic reaction of phenol was used as a model reaction to evaluate the catalytic activities of the obtained catalysts. Compared with pure TiO2 or Ti-Sn catalyst prepared with general sol-gel method, Ti-Sn nano-composite photo-catalyst thus obtained showed significant improvement in catalytic activity. The photo-catalytic degradation rate of phenol could reach as high as 93.5% after 7 h. The preparation conditions of the new phase (Ti, Sn)O2 were investigated and its catalytic mechanism was proposed. The photo-catalytic particles prepared using SCFD combination technology exhibited small particle size, large surface area and high activity.
关键词:
Anatase TiO2
,
null
,
null
,
null
,
null
,
null
郑永杰
,
胡义
,
荆涛
,
田景芝
材料科学与工程学报
doi:10.14136/j.cnki.issn 1673-2812.2015.06.003
本文基于密度泛函理论(DFT)的GGA+U方法,应用Materials Studio 5.0软件包中的CASTEP程序模拟计算了Al掺杂锐钛矿型TiO2和N-Al共掺杂锐钛矿型TiO2的电子结构.计算结果表明:Al掺杂和N-Al共掺杂均能够降低TiO2的带隙值.Al掺杂是由于Al的3s和3p态使导带底端下移而导致TiO2的带隙变窄;而N-Al共掺杂由于在体系中引入了N2p态,使导带底端向能量更低的方向移动,比Al单独掺杂时具有更低的带隙值.该研究结果很好地解释了Al掺杂以及N-Al共掺杂诱使TiO2的导带底端下移,禁带宽度减小,导致光谱响应范围红移的内在原因.
关键词:
锐钛矿型TiO2
,
N-Al共掺杂
,
GGA+U
