Interaction of anatase and rutile TiO2 particles in aqueous photooxidation
Interaction of anatase and rutile TiO2 particles in aqueous photooxidation
复制标题
DOI：
10.1016/j.cattod.2003.08.006
复制
发表时间：
2003-12
期刊：
影响因子：
5.3
通讯作者：
Bo-wen Sun;P. Smirniotis
中科院分区：
文献类型：
--
作者：
Bo-wen Sun;P. Smirniotis
通过苯酚和甲酸的光分解，研究了具有不同粒径和杂质含量的TiO2催化剂的各种组合的锐钛矿型和金红石型二氧化钛的相互作用。商业石原 ST 系列锐钛矿二氧化钛 (95% TiO2) 的反应性随着初级粒径 (ST-01, 7nm; ST-21, 20nm; ST-41, 200nm) 的增加和表面积的减小而增加。 ST系列锐钛矿型TiO2在365nm波长下的消光系数比表面积为52m2/g的Kemira (KE)金红石型TiO2低约1个数量级。使用 ST 系列锐钛矿型 TiO2 和 KE 金红石型 TiO2 的混合物观察到锐钛矿型和金红石型二氧化钛之间不同的相互作用。当辐照场由混合物中的 KE 主导时，这些相互作用完全颠倒了 ST 系列催化剂在苯酚光氧化中的活性顺序。提出了 Ishihara ST 系列 TiO2 催化剂颗粒中的杂质分布来解释上述现象。锐钛矿和金红石 TiO2 颗粒之间的不同相互作用与它们相互接触之前的相对费米能级有关。在苯酚和甲酸的光降解过程中，观察到 Hombikat UV-100 锐钛矿型 TiO2（HK，99% TiO2）与 HK 制得的金红石相 TiO2（HK_R）之间存在不同的相互作用。 HK 和 HK_R 之间相互作用的变化可以通过较低 pH 值下 TiO2 颗粒的更强水解和更弱的团聚来解释。实验表明，Degussa P25中锐钛矿和金红石之间的协同效应并不具有普遍性，它与锐钛矿和金红石颗粒的相对费米能级以及颗粒形状有关。
The interaction of anatase and rutile titanias was studied with various combinations of TiO2catalysts having different particle sizes and impurity contents by photodecomposition of phenol and formic acid. The reactivity of commercial Ishihara ST-series anatase titanias (95% TiO2) increased with the increase of primary particle size (ST-01, 7nm; ST-21, 20nm; ST-41, 200nm) and the decrease of surface area. Light extinction coefficients of the ST-series anatase TiO2’s at the wavelength of 365nm were about 1 order of magnitude lower than that of Kemira (KE) rutile TiO2having a surface area of 52m2/g. Different interactions between anatase and rutile titanias were observed with the mixtures of the ST-series anatase TiO2’s and KE rutile TiO2. When the irradiation field was dominated by the KE in the mixtures, these interactions inverted completely the order of activities of the ST-series catalysts in phenol photooxidation. The impurity distribution in particles of the Ishihara ST-series TiO2catalysts was proposed to explain the above phenomena. The different interactions between anatase and rutile TiO2particles were related to their relative Fermi levels prior to their contacting each other. Different interactions between Hombikat UV-100 anatase TiO2(HK, 99% TiO2) and rutile-phase TiO2made from HK (HK_R) by heating were observed in phenol and formic acid photodegradations. The change of interaction between HK and HK_R was explained by the stronger hydrolyzation and weaker agglomeration of TiO2particles at lower pH values. The experiments done showed that the synergistic effect between anatase and rutile in Degussa P25 was not universal and it was related to the relative Fermi levels of anatase and rutile particles and the particle shape.