Functionalized C@TiO2 hollow spherical architecture for multifunctional applications.
Functionalized C@TiO2 hollow spherical architecture for multifunctional applications.
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DOI：
10.1039/c5dt05011a
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发表时间：
2016-03
影响因子：
4
通讯作者：
S. Chattopadhyay;M. Mishra;G. De
中科院分区：
文献类型：
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作者：
S. Chattopadhyay;M. Mishra;G. De
以硫脲和柠檬酸为溶剂，异丙醇钛（TTIP）为原料，采用溶剂热法合成了具有中空球形结构的碳量子点（C（F）@THS）纳米TiO2。有趣的是，已经发现硫脲和柠檬酸的伴随存在对于获得这种分层中空结构是必不可少的，因为当用TTIP水热处理时，各个成分产生非中空球体。这两种成分的共存也加速了空心球的生长。C（F）@THS的BET表面积研究表明存在狭缝状中孔，表面积值为81 m2 g-1。随时间变化的FESEM和TEM研究证实了在中间阶段形成纳米片状结构，随后是中空球形结构的生长。我们提出这些纳米片在气泡表面上积累以形成这种中空球形形态。所制备的C（F）@THS的PL光谱研究和拉曼位移证实了表面上官能化石墨C点的存在。进行彻底的XPS分析以探索官能团（-COOH、-CONH2、-NH2）的性质和相对原子浓度。这种C（F）@THS样品显示出非常快速和选择性的染料（亚甲基蓝和甲基紫）吸附能力（即使是从两种不同染料溶液的混合物中），这是由于表面上这些含有δ-位点的官能团。由于C（F）@THS的重复使用性仅为2次，因此将吸附染料的C（F）@THS在空气中于450 ° C煅烧，得到不含有机物的TiO2空心球（THS）。THS作为一种高效的可重复使用的光催化剂（k = 9.36 × 10（-2）min（-1））以及染料敏化太阳能电池（DSSC）的光阳极被回收，其Jsc值为19.58 mA cm（-2），总效率为6.48%。
Hierarchical anatase titania (TiO2) with a hollow spherical architecture decorated with functionalized carbon dots (C(F)@THS) was synthesized by a solvothermal decomposition of titanium(IV) isopropoxide (TTIP) in the presence of a solution mixture containing thiourea and citric acid. Interestingly, the concomitant presence of thiourea and citric acid has been found to be essential to obtain such hierarchical hollow architecture because individual constituents produced non-hollow spheres when hydrothermally treated with TTIP. The co-existence of these two constituents also accelerates the growth of hollow spheres. BET surface area study of C(F)@THS revealed the existence of a slit like mesoporosity with a surface area value of 81 m(2) g(-1). Time dependent FESEM and TEM studies confirmed the formation of nanoflake like structures in the intermediate stages followed by the growth of a hollow spherical architecture. We proposed that these nanoflakes get accumulated on the bubble surface to form such hollow spherical morphology. The PL spectral study and Raman shift of the as prepared C(F)@THS confirmed the presence of functionalized graphitic C dots on the surface. A thorough XPS analysis was conducted to explore the nature and relative atomic concentration of the functional groups (-COOH, -CONH2, -NH2). This C(F)@THS sample showed very fast and selective dye (methylene blue and methyl violet) adsorption ability (even from a mixture of two different dye solutions) due to these δ-site containing functional groups on the surface. As C(F)@THS showed only two times reusability for adsorption, the dye adsorbed C(F)@THS was calcined at 450 °C in air to yield organic free anatase TiO2 hollow spheres (THS) with a retention of the original structure. THS was recycled as an efficient and a reusable photocatalyst (k = 9.36 × 10(-2) min(-1)) as well as a photoanode in dye sensitized solar cells (DSSCs) having Jsc value of 19.58 mA cm(-2) with overall efficiency of 6.48%.