The Design of TiO2 Nanostructures (Nanoparticle, Nanotube, and Nanosheet) and Their Photocatalytic Activity
The Design of TiO2 Nanostructures (Nanoparticle, Nanotube, and Nanosheet) and Their Photocatalytic Activity
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DOI：
10.1021/jp500252g
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发表时间：
2014-06
影响因子：
3.7
通讯作者：
Yanlong Yu;Peng Zhang;Limei Guo;Zhandong Chen;Qiang Wu;Yi‐hong Ding;Wenjun Zheng;Yaan Cao
中科院分区：
文献类型：
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作者：
Yanlong Yu;Peng Zhang;Limei Guo;Zhandong Chen;Qiang Wu;Yi‐hong Ding;Wenjun Zheng;Yaan Cao
采用密度泛函理论（DFT）计算了TiO 2纳米颗粒、纳米管和纳米片模型的能带结构和态密度（DOS），预测了三种不同纳米结构光催化活性的顺序。溶胶-凝胶法和水热法用于获得所需的形貌：纳米颗粒、纳米管和纳米片（破碎的纳米管）。光催化活性的大小顺序为纳米片>纳米管>纳米颗粒，与理论预测一致。结果表明，量子限制效应导致了禁带宽度的增大;纳米结构的形貌决定了光生电子寿命的延长和比表面积的增加。所有这些因素都有助于提高纳米结构的光催化活性。研究结果对设计和选择具有理想形貌和改善光电性能的低维纳米材料具有指导意义。
Density functional theory (DFT) calculation is carried out to access the band structure and density of states (DOS) based on the models of TiO2 nanoparticle, nanotube, and nanosheet, predicting the order of the photocatalytic activity for three different nanostructures. Sol–gel method and hydrothermal method are used to achieve desired morphologies: nanoparticles, nanotubes, and nanosheets (fragmentized nanotubes). The photocatalytic activity ranks in the order of nanosheets > nanotubes > nanoparticles, which is consistent with theoretical prediction. It was revealed that the enlargement of band gap is caused by the quantum confinement effect; the prolonged lifetime of photogenerated electrons and increased specific surface areas are dependent on the morphology of the nanostructure. All these factors contribute to the improvement of the photocatalytic activity for nanostructures. Our results can guide the design and selection of low-dimensional nanomaterials with desired morphology and improved photoelect...