Zou Xiao-Xin, Li Guo-Dong, Guo Ming-Yi, Li Xin-Hao, Liu Da-Peng, Su Juan, Chen Jie-Sheng
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, PR China.
Chemistry. 2008;14(35):11123-31. doi: 10.1002/chem.200801236.
Transition-metal-doped titanium glycolates (M-TG, with M=Fe, Mn), which are the first non-stoichiometric heterometal alkoxides, have been synthesised through a solvothermal doping approach. X-ray diffraction, UV/Vis diffuse reflectance and ESR spectroscopy revealed that the dopant ion (Fe(3+) or Mn(2+)) is substituted for Ti(4+) in the TG lattice. Fe(3+) prolongs the crystallisation time of Fe-TG, whereas Mn(2+) has a smaller effect on the crystallisation time in comparison with Fe(3+). The as-synthesised M-TG materials were used directly as single-source precursors for the preparation of metal-doped titania (M-TiO(2)) through a simple thermal treatment process. The as-prepared M-TiO(2) materials maintain the rod-like morphology of the precursors and possess a mesoporous structure with high crystallinity. It has been proved that the dopant ions are incorporated into the TiO(2) lattice at the Ti(4+) positions. The photocatalytic activities of the M-TiO(2) materials obtained were evaluated by testing the degradation of phenol under UV irradiation. From the photocatalytic results, it was concluded that high crystallinity, a large surface area and appropriate transition-metal-doping are all beneficial to the enhancement of the photocatalytic performance of the doped TiO(2) material. In addition, it was noted that in comparison with Mn-TiO(2), Fe-TiO(2) shows higher photocatalytic activity due to the better inhibition effect of Fe(3+) on recombination of photogenerated electron-hole pairs. In contrast to the conventional nanosized TiO(2) photocatalyst, the micrometre-sized M-TiO(2) particles we obtained can be easily separated and recovered after the photocatalytic reactions.
过渡金属掺杂的乙醇钛酸盐（M-TG，M = Fe、Mn）是首批非化学计量比的杂金属醇盐，已通过溶剂热掺杂法合成。X射线衍射、紫外/可见漫反射和电子顺磁共振光谱表明，掺杂离子（Fe(3+)或Mn(2+)）在TG晶格中取代了Ti(4+)。Fe(3+)延长了Fe-TG的结晶时间，而Mn(2+)与Fe(3+)相比，对结晶时间的影响较小。合成的M-TG材料通过简单的热处理过程直接用作制备金属掺杂二氧化钛（M-TiO₂）的单源前驱体。所制备的M-TiO₂材料保持了前驱体的棒状形态，并具有高结晶度的介孔结构。已证明掺杂离子在Ti(4+)位置掺入TiO₂晶格中。通过测试紫外光照射下苯酚的降解来评估所得M-TiO₂材料的光催化活性。从光催化结果得出，高结晶度、大表面积和适当的过渡金属掺杂均有利于提高掺杂TiO₂材料的光催化性能。此外，还注意到与Mn-TiO₂相比，Fe-TiO₂由于Fe(3+)对光生电子-空穴对复合的抑制作用更好而表现出更高的光催化活性。与传统的纳米尺寸TiO₂光催化剂相比，我们获得的微米尺寸M-TiO₂颗粒在光催化反应后可以很容易地分离和回收。
