The crucial role of W6+, P5+and N3− dopant ions in the anatase TiO2 crystal lattice for enhanced photocatalytic activity under the irradiation of UV/solar light: Structure-reactivity correlation
The crucial role of W6+, P5+and N3− dopant ions in the anatase TiO2 crystal lattice for enhanced photocatalytic activity under the irradiation of UV/solar light: Structure-reactivity correlation
复制标题
DOI：
10.1016/j.matchemphys.2019.02.061
复制
发表时间：
2019-05
影响因子：
4.6
通讯作者：
Cisy Abraham;L. Devi
中科院分区：
文献类型：
--
作者：
Cisy Abraham;L. Devi
采用简单的溶胶-凝胶法制备tio2和W6+（0.02 at）。%)掺杂TiO2。制备的样品在500 °C （WT500）和700 °C （WT700）下退火。粉末x射线衍射（PXRD）研究证实了TiO2和WT500样品的锐钛矿结构，而WT700样品同时含有TiO2的锐钛矿和金红石相。P5+（0.5和1.5）掺杂 at。%)和N3−(0.2 at。采用湿浸渍法制备0.5PWT500、1.5PWT500、PWNT500、0.5PWT900和1.5PWT900催化剂样品，分别在500 °C和900 °C退火。P5+掺杂剂能有效抑制0.5PWT900样品从锐钛矿到金红石的相变，而WT700在700 ℃时则会发生这种相变。0.5PWT900样品与锐钛矿tio2一起形成焦磷酸钛（TiP2O7）。随着h3po4浓度的升高和煅烧温度的升高，tip2o7的PXRD峰的数量和强度均有所增加。x射线光电子能谱技术（XPS）证实了掺杂离子的氧化态为W6+、P5+和N3−。研究了上述催化剂在紫外光/太阳光照射下降解模型污染物刚果红染料的光催化活性。由于掺杂剂的协同作用，三掺杂的PWNT500催化剂表现出更高的效率。本研究试图将催化剂的结构与光催化反应性联系起来。
A simple sol-gel route was adopted for the preparation of TiO2and W6+(0.02 at. %) doped TiO2. The prepared samples were annealed at 500 °C (WT500) and also at 700 °C (WT700). Powder X-ray diffraction (PXRD) study confirms the anatase structure for TiO2and WT500 samples, whereas WT700 contains both anatase and rutile phases of TiO2. Doping of P5+(0.5 and 1.5 at. %) and N3−(0.2 at. %) ions into the anatase lattice structure of WT500 sample was done by wet impregnation method to get 0.5PWT500, 1.5PWT500, PWNT500, 0.5PWT900 and 1.5PWT900 catalyst samples which were annealed at 500 °C and 900 °C. P5+dopant could effectively inhibit the phase transition of 0.5PWT900 sample from anatase to rutile, which otherwise takes place in the case of WT700 at 700 °C. Formation of titanium pyrophosphate (TiP2O7) was confirmed along with anatase TiO2for 0.5PWT900 sample. The number of PXRD peaks pertaining to TiP2O7and their intensities increased with the increase in H3PO4concentration and the calcination temperature. X-ray photoelectron spectroscopic technique (XPS) has confirmed the oxidation states of dopant ions as W6+, P5+and N3−. The photocatalytic activities of all the above catalysts were studied for the degradation of congo red (CR) dye as the model pollutant under UV/solar light irradiation. The tridoped PWNT500 catalyst showed higher efficiency due to the synergistic effects of dopants. An attempt is made in the present research to correlate the structure of the catalyst with the photocatalytic reactivity.