Shape-Controlled Anatase Titanium(IV) Oxide Particles Prepared by Hydrothermal Treatment of Peroxo Titanic Acid in the Presence of Polyvinyl Alcohol
Shape-Controlled Anatase Titanium(IV) Oxide Particles Prepared by Hydrothermal Treatment of Peroxo Titanic Acid in the Presence of Polyvinyl Alcohol
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DOI：
10.1021/jp809104t
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发表时间：
2009-02-26
影响因子：
3.7
通讯作者：
Ohno, Teruhisa
中科院分区：
文献类型：
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作者：
Murakami, Naoya;Kurihara, Yu;Ohno, Teruhisa
以过氧钛酸（PTA）溶液为溶剂，聚乙烯醇为控形剂，采用水热法制备了具有特定晶面的锐钛型氧化钛（TiO2）颗粒。TiO2颗粒的晶相、形状和大小与PTA溶液的pH值和水热处理时间有很大关系。在pH为7的PTA溶液中制备的TiO2颗粒晶面分别为{101}和{001}，随着水热处理时间的延长，TiO2颗粒的形状发生了变化。所制备的具有特定晶面的TiO2颗粒对乙醛分解的光催化活性高于商品球形TiO2颗粒。这一结果表明，由于电子和正电空穴选择性地迁移到特定的暴露晶面和/或特定暴露晶面上的电子和正电空穴的不同反应性，粒子中氧化还原位点的空间分离阻止了反反应。此外，TiO2颗粒的形状演变与光催化活性有关，八面体锐钛矿的堆叠结构由于具有大表面积的氧化和还原位点而表现出最高的光催化活性。
Anatase titanium(IV) oxide (TiO2) Particles With specific exposed crystal faces were prepared by hydrothermal treatment of peroxo titanic acid (PTA) solution with polyvinyl alcohol as a shape-control reagent. Crystal phase, shape, and size of TiO2 particles were found to be greatly dependent on pH value of PTA solution and time of hydrothermal treatment. TiO2 particles prepared from PTA solution of pH 7 had {101} and {001} exposed crystal faces, and the shape of TiO2 particles changed with the time of hydrothermal treatment. The prepared TiO2 particles with specific exposed crystal faces showed higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO2 particles. This result implies that back reaction was prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face. Furthermore, the shape evolution of TiO2 particles showed a relationship with photocatalytic activity, and a stacked structure of octahedral anatase showed the highest photocatalytic activity due to both oxidation and reduction sites with large surface area.