物理化学学报 >> 2017, Vol. 33 >> Issue (10): 2072-2081.doi: 10.3866/PKU.WHXB201705127

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氢氟酸加入量对钛基半导体结构演变及光催化性能的影响

张昊,李新刚*(),蔡金孟,王亚婷,武墨青,丁彤,孟明,田野   

  • 收稿日期:2017-04-25 发布日期:2017-07-17
  • 通讯作者: 李新刚 E-mail:xingang_li@tju.edu.cn
  • 基金资助:
    国家自然科学基金(21476159);天津市自然科学基金(15JCZDJC37400);天津市自然科学基金(15JCYBJC23000)

Effect of the Amount of Hydrofluoric Acid on the Structural Evolution and Photocatalytic Performance of Titanium Based Semiconductors

Hao ZHANG,Xin-Gang LI*(),Jin-Meng CAI,Ya-Ting WANG,Mo-Qing WU,Tong DING,Ming MENG,Ye TIAN   

  • Received:2017-04-25 Published:2017-07-17
  • Contact: Xin-Gang LI E-mail:xingang_li@tju.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21476159);Natural Science Foundation of Tianjin, China(15JCZDJC37400);Natural Science Foundation of Tianjin, China(15JCYBJC23000)

摘要:

以钛酸丁酯为钛源,氢氟酸为氟源,采用溶剂热法制备了一系列钛基半导体纳米晶,考察了氢氟酸加入量对纳米晶结构演变的影响,并通过光催化产氢、光降解罗丹明B及瞬态光电流响应测试了所得纳米晶的光催化性能。当不加氢氟酸时,所得纳米晶为TiO2纳米颗粒,主要暴露{101}面。加入少量氢氟酸时,所得纳米晶为主要暴露{001}面的TiO2纳米片,这是由于氟离子吸附于纳米晶表面,降低{001}面表面能所致。由于{001}面与{101}面间的晶面异质结促进了载流子分离,该样品表现出了最高的光催化性能。继续增加氢氟酸加入量,氟离子开始进入晶格构成新晶相,所得纳米晶的表面与体相均形成TiO2与TiOF2混合相,形貌呈现片层堆叠结构,光催化性能下降。当进一步增加氢氟酸加入量后,氟离子全部进入晶格形成大颗粒(NH40.3TiO1.1F2.1。因其具有不适宜光催化反应的能带结构,该物质表现出了较差的光催化活性,但其可作为制备氮、氟掺杂钛基半导体材料的前驱体使用。

关键词: 氢氟酸, 钛基半导体, 结构演变, 光催化, 光电性能

Abstract:

Herein, the synthesis of a series of titanium based nanocrystals using tetrabutyl titanate (TBT) as the titanium source and hydrofluoric acid (HF) as the fluorine source under solvothermal conditions has been described. The effect of the amount of HF on the structural evolution of the nanocrystals was studied. The catalytic performance of the as-prepared samples was measured by photocatalytic hydrogen evolution, photocatalytic RhB degradation, and chronoamperometric tests. The obtained results showed that anatase TiO2 nanoparticles with exposed {101} facets were synthesized in the absence of HF. After the addition of a small amount of HF, the F- ion adsorbed on the surface of the nanocrystal and decreased the surface energy of the {001} facets. Thus, sheet-shaped TiO2 was formed with exposed {001} facets. Furthermore, the as-prepared sample showed an enhanced photocatalytic performance because of the increased charge separation efficiency, which was dependent on the surface heterostructure generated between the {101} and {001} facets. On further increasing the amount of HF, F- ions started to enter the lattice and formed a new crystal phase. The as-prepared sheet-stacked sample was comprised of TiO2 and TiOF2 phases in both surface and bulk regions, which showed the decreased photocatalytic activity. With the addition of more HF, the F- ion moved completely into the crystal lattice and the large particle structure of (NH4)0.3TiO1.1F2.1 was formed. Although the as-prepared (NH4)0.3TiO1.1F2.1 displayed a low photocatalytic activity because of an improper band gap structure, it could be used as a precursor for the synthesis of N, F doped titanium based semiconductors.

Key words: Hydrofluoric acid, Titanium based semiconductor, Structure evolution, Photocatalysis, Photoelectrochemical performance

MSC2000: 

  • O643