N-Doped TiO2 Prepared from Microwave-Assisted Titanate Nanotubes (NaxH2-xTi3O7): The Effect of Microwave Irradiation during TNT Synthesis on the Visible Light Photoactivity of N-Doped TiO2
N-Doped TiO2 Prepared from Microwave-Assisted Titanate Nanotubes (NaxH2-xTi3O7): The Effect of Microwave Irradiation during TNT Synthesis on the Visible Light Photoactivity of N-Doped TiO2
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DOI：
10.1021/jp1076005
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发表时间：
2011-03-17
影响因子：
3.7
通讯作者：
Liao, Ching-Hui
中科院分区：
文献类型：
--
作者：
Ou, Hsin-Hung;Lo, Shang-Lien;Liao, Ching-Hui
本研究的目的是表征氮掺杂的二氧化钛制备微波辅助钛酸盐纳米管（TNTs，NaxH 2-xTi 3 O 7）在Ar/NH3气氛中热处理。同时研究了Na（I）的插层对TNT可见光活性和N掺杂模式的影响。通过对可见光区苯酚光催化氧化性能的评价，发现由TNT制备的N掺杂TiO 2的光催化活性是由P25 TiO 2制备的Ni掺杂TiO 2的3倍。HR-TEM、XRD、XPS、NH3-TPD、UV-vis DRS和S-BET等表征表明，O-Ti-N键的取代型N掺杂模式是导致禁带宽度变窄、可见光活性增强的主要原因。此外，掺杂机制显著依赖于TNT内插层Na（I）的存在。由于替代掺杂，O-Ti-N键对于具有低含量的插层Na（I）的TNT是明显的，而较高含量的插层Na（I）的存在导致Ti-N-O键的形成，其被认为是间隙掺杂模式。此外，在掺杂过程中插入的Na（I）的存在导致形成Na 2 Ti6 O 13而不是惰性的TiN结晶，这有利于提高N掺杂的TiO 2的光活性，由于Na 2 Ti6 O 13和TiO 2之间的相间电子转移的作用。
This study aimed to characterize N-doped TiO2 prepared by thermally treating microwave-assisted titanate nanotubes (TNTs, NaxH2-xTi3O7) in an Ar/NH3 atmosphere. The effect of intercalated Na(I) within TNTs on the visible light photoactivity and the N-doping mode was investigated as well. By evaluating the performance of photocatalytic oxidation of phenol under the visible region, the photoactivity of N-doped TiO2 prepared from TNTs is 3 times higher than that of NI-doped TiO2 prepared from P25 TiO2. Characterizations, including HR-TEM, XRD, XPS, NH3-TPD, UV-vis DRS, and S-BET, indicate that the substitutional N-doping mode, the O-Ti-N linkage, is mainly responsible for narrowing the band gap and eventually enhancing the visible light photoactivity. Furthermore, the doping mechanism is significantly dependent on the presence of intercalated Na(I) within TNTs. The O-Ti-N linkage, owing to the substitutional doping, is apparent for TNTs with a low content of intercalated Na(I), whereas the presence of the higher amount of intercalated Na(I) leads to the formation of the Ti-N-O linkage that is considered as an interstitial doping mode. Also, the presence of intercalated Na(I) during the doping process results in the formation of Na2Ti6O13 instead of an inert TiN crystallinity, which is advantageous to enhancing the photoactivity of N-doped TiO2 due to the effect of interphase electron transfer between Na2Ti6O13 and TiO2.