Synthesis and photocatalytic properties of SiO2/TiO2 nanofibers using templates of TEMPO-oxidized cellulose nanofibers
Synthesis and photocatalytic properties of SiO2/TiO2 nanofibers using templates of TEMPO-oxidized cellulose nanofibers
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DOI：
10.1007/s10971-016-4033-0
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发表时间：
2016-07-01
影响因子：
2.5
通讯作者：
Miura, Kiyotaka
中科院分区：
文献类型：
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作者：
Gunji, Shunsuke;Shimotsuma, Yasuhiko;Miura, Kiyotaka
以TEMPO-OXED纤维素纳米纤维(TOCN)为模板制备了二氧化硅/二氧化钛纳米纤维。二氧化硅和/或二氧化钛的沉积是通过两种硅醇盐和一种钛醇盐的水解和缩合反应实现的。经TOCN模板燃烧后，得到了比表面积高达158m(2)/g的二氧化钛/二氧化钛纳米纤维，即二氧化钛和二氧化硅的复合纳米纤维。二氧化硅/二氧化钛纳米纤维的直径约为8 nm，由由二氧化硅和二氧化钛连续沉积而来的核/壳结构组成。二氧化硅晶核和二氧化钛壳层分别由非晶态和锐钛矿型纳米晶组成。我们证实，在相同比表面积的情况下，所合成的二氧化硅/二氧化钛纳米纤维对亚甲基蓝(MB)阳离子污染物的光催化降解活性高于传统的多孔二氧化钛颗粒。探讨了SiO_2/TiO_2纳米纤维增强MB降解的机理。
SiO2/TiO2 nanofibers were fabricated using TEMPO-oxidized cellulose nanofibers (TOCN) as templates. SiO2 and/or TiO2 deposition onto the surface of TOCN was achieved by the hydrolysis and condensation reactions of two types of silicon alkoxide and a titanium alkoxide. After the combustion of TOCN templates, SiO2/TiO2 nanofibers with the high specific surface area of 158 m(2)/g that were the composite nanofibers of TiO2 and SiO2 were obtained. The SiO2/TiO2 nanofibers have a diameter of around 8 nm and consist of a core/shell structure derived from the sequential deposition of SiO2 and TiO2. The structures of SiO2 core and TiO2 shell consist of amorphous and anatase nanocrystals, respectively. We confirmed that the synthesized SiO2/TiO2 nanofibers exhibit higher photocatalytic activity for degrading the cationic pollutant of methylene blue (MB) than conventional porous TiO2 particles with a similar specific surface area. The mechanisms for the enhanced MB degradation of the SiO2/TiO2 nanofibers are discussed.