Heterostructured TiO2 Nanoparticles/Nanotube Arrays: In Situ Formation from Amorphous TiO2 Nanotube Arrays in Water and Enhanced Photocatalytic Activity
Heterostructured TiO2 Nanoparticles/Nanotube Arrays: In Situ Formation from Amorphous TiO2 Nanotube Arrays in Water and Enhanced Photocatalytic Activity
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异质结构 TiO2 纳米粒子/纳米管阵列：非晶态 TiO2 纳米管阵列在水中原位形成并增强光催化活性
DOI：
10.1002/cplu.201200024
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发表时间：
2012-04-01
期刊：
影响因子：
3.4
通讯作者：
Chu, Paul K.
中科院分区：
文献类型：
--
作者：
Huo, Kaifu;Wang, Hairong;Chu, Paul K.
异质结构 TiO2 纳米颗粒/纳米管阵列 (NPs/NTA) 是由阳极氧化非晶 TiO2 纳米管阵列在低至 90°C 的温度下在水中制备而成。阳极氧化非晶 TiO2 纳米管在水中的相和形貌转变可归因于水诱导的溶解和重结晶机制，其中阳极氧化非晶 TiO2 NTA 逐渐自牺牲，然后自发地发生。转变为由锐钛矿纳米颗粒和较薄的无定形纳米管组成的复合纳米颗粒/纳米管结构。通过在450℃空气中退火3小时，复合材料可进一步结晶为由锐钛矿NT和锐钛矿纳米颗粒组成的锐钛矿TiO2纳米颗粒/NTA。复合锐钛矿型TiO2 NPs/NTA的比表面积是锐钛矿型TiO2 NTA的1.4倍，在有机污染物的光分解和水分解方面具有增强的光催化活性。锐钛矿型TiO2 NPs/NTA光催化剂对有机污染物罗丹明B的光分解速率是退火锐钛矿型TiO2 NTA光催化剂的两倍。异质结构 TiO2 NPs/NTA 增强的光催化活性源于 TiO2 NPs 的大表面积和锐钛矿 TiO2 NT 中优异的电子传输。在水中将非晶态 TiO2 NTA 的微观结构原位水热转化为异质结构的 TiO2 NPs/NTA 非常简单，从而能够设计和制造适用于光催化和太阳能转换的高光活性一维 TiO2 基功能材料。
Heterostructured TiO2 nanoparticles/nanotube arrays (NPs/NTAs) are produced from as-anodized amorphous TiO2 nanotube arrays in water at a temperature as low as 90?degrees C. The phase and morphology transformation of the as-anodized amorphous TiO2 nanotube in water can be attributed to a water-induced dissolution and recrystallization mechanism in which the as-anodized amorphous TiO2 NTAs are gradually self-sacrificed, and then spontaneously morphing into the composite NPs/NTAs structure consisting of anatase NPs and thinner amorphous NTs. The composite can be further crystallized into anatase TiO2 NPs/NTAs consisting of anatase NT and anatase NPs by annealing in air at 450?degrees C for 3 hours. The composite anatase TiO2 NPs/NTAs have a surface area that is 1.4 times larger than that of the anatase TiO2 NTAs and possess enhanced photocatalytic activity in the photodecomposition of organic pollutants and water splitting. The photodecomposition rate of the organic pollutant rhodamine B by the anatase TiO2 NPs/NTAs photocatalyst is two times higher than that by the annealed anatase TiO2 NTAs. The enhanced photocatalytic activity of the hererostructured TiO2 NPs/NTAs arises from the large surface area of the TiO2 NPs and superior electron transport in anatase TiO2 NT. The in situ hydrothermal conversion of the microstructure from amorphous TiO2 NTAs into hererostructured TiO2 NPs/NTAs in water is very simple thereby enabling the design and fabrication of highly photoactive one-dimensional TiO2-based functional materials applicable to photocatalysis and solar energy conversion.