State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.
Nanoscale. 2012 Aug 7;4(15):4650-7. doi: 10.1039/c2nr30733b. Epub 2012 Jun 25.
In this paper, on the basis of a simple side-by-side co-electrospray procedure with a subsequent non-equilibrium calcination process, we have for the first time developed an asymmetric shrinkage approach for the fabrication of magnetic γ-Fe(2)O(3)/TiO(2) Janus hollow bowls (JHBs) by constructing a precursor solution pair with different gelation rates during the solvents evaporation process. The formation mechanisms of the bowl-shapes as well as the hollow interiors are proposed and confirmed. The as-obtained γ-Fe(2)O(3)/TiO(2) JHBs have a transition layer of Fe(3+)-doped-TiO(2) between the γ-Fe(2)O(3) and TiO(2) phases, and show an efficient visible-light photocatalytic activity and convenient magnetic separation for water purification because of the unique structure and morphology as well as the fine magnetic properties. Moreover, the method reported here can be readily extended to the fabrication of other bi-, tri- and multi-component metal oxides hollow particles with asymmetric shapes. Due to the interesting bowl-shaped hollow nanostructure, the as-prepared γ-Fe(2)O(3)/TiO(2) JHBs are expected to have a number of applications that involve drug delivery, micro-/nano-motors, microcontainers, microreactors, sensors, and so forth.
在本文中，我们首次通过一种简单的并排共电喷雾方法，并随后采用非平衡煅烧工艺，利用前驱体溶液在溶剂蒸发过程中具有不同的胶凝速率，开发了一种制备具有不对称收缩特性的磁性 γ-Fe(2)O(3)/TiO(2) 二相（Janus）中空碗（JHBs）的方法。提出并证实了碗状结构和中空内部的形成机理。所获得的 γ-Fe(2)O(3)/TiO(2) JHBs 在 γ-Fe(2)O(3)和 TiO(2)相之间具有 Fe(3+)-掺杂 TiO(2)的过渡层，由于独特的结构和形态以及良好的磁性，显示出高效的可见光光催化活性和便于水净化的磁分离性能。此外，这里报道的方法可以很容易地扩展到其他具有不对称形状的双相、三相和多相金属氧化物中空颗粒的制备。由于具有有趣的碗状中空纳米结构，所制备的 γ-Fe(2)O(3)/TiO(2) JHBs 有望在药物输送、微/纳米马达、微容器、微反应器、传感器等方面得到广泛应用。
