Sep 19, 2012
1D magnetite nanostructures obtained without templates for energy applications
Due to its complicated inverse spinel structure, the growth of Fe3O4 as a one-dimensional (1D) nanostructure remains a challenge. Conventional methods include reduction of other 1D iron oxides, as well as template-assisted and external magnetic field assisted techniques. Now, a one-pot and template-free hydrothermal method has been developed by researchers at Zhejiang University, China, to synthesize Fe3O4 nanobelts.
The group is working on the synthesis of 1D iron oxide nanostructures for energy applications. The team discovered that the addition of Na2CO3 and FeCl2 in the hydrothermal process could bring about the formation of nanobelt structures of magnetite after attempting various additives and precursors. The method provides a simple and low-cost synthesis route compared with conventional approaches.
As shown in the image, Fe3O4 nanobelts with widths of 0.1–2 µm, thicknesses of about 10 nm and lengths of 20–30 µm are obtained. The researchers found that the amount of Na2CO3 played an important role in controlling both the morphology and crystal structures of the products. Time-dependent experiments revealed that the nanobelts grow from fractured nanosheets that are initially linked together at the very beginning of the reaction.
The Fe3O4 nanobelts exhibit magnetic properties with a magnetic saturation value of 77.0 emu/g and deliver lithium storage performances with a high initial discharge capacity of 1090 mAh/g at a current rate of 500 mA/g and a reversible capacity of 404 mAh/g retained after 60 charge/discharge cycles. These results suggest that the Fe3O4 nanobelts might be promising for use as magnetic materials and for use in lithium batteries.
More information can be found in the journal Nanotechnology.
About the author
Ye Shi is a Masters student in the Department of Polymer Science and Engineering at Zhejiang University, Hangzhou, China, under the supervision of Prof. Hongzheng Chen. His research focuses on the synthesis of nanomaterials for energy applications.