|Search for content and authors|
Size- and Shape-Controlled Continuous Flow Hydrothermal Synthesis of Inorganic Nanomaterials
|Ed Lester 1, Christopher Starkey , Peter W. Dunne , Miquel Gimeno-Fabra|
1. University of Nottingham, Nottingham, United Kingdom
Continuous flow hydrothermal synthesis has proven itself to be a simple, scalable and relatively environmentally friendly method for the production inorganic nanomaterials. Much of the research effort in this area has focussed on the synthesis of metal oxide nanoparticles. We have recently been shown that continuous flow hydrothermal synthesis can be applied to the production of nanostructured phosphate materials, such as hydroxyapatite nanotubes. We are currently working to further extend the library of inorganic nanomaterials accessible by this technology.
Here we report for the first time a general continuous flow hydrothermal synthesis route to a variety of metal sulphide nanomaterials. Metal sulphides constitute a diverse and interesting class of materials with a wide range of structures and applications, with many sulphide systems exhibiting strongly size- and shape-dependent optical and electronic properties. Nanosized and nanostructured metal sulphides are thus of particular interest for their applications in biological labeling, photocatalysis, photovoltaics, LEDs and lithium-ion batteries.
The reaction of metal salts with thiourea under continuous flow hydrothermal conditions has been found to be a viable route to a wide range of metal sulphide nanoparticles; including zinc, cadmium, and lead sulphides. Furthermore, by varying reaction conditions it is possible to control the size and shape of the produced nanoparticles.
The continuous hydrothermal synthesis of lithium iron phosphate for lithium-ion battery applications is also reported. LiFePO4 is a highly promising material for next generation battery materials, with high stability, as well as a high redox potential and theoretical capacity. The poor conductivity and lithium ion diffusivity of the material may potentially be overcome by limiting particle size to the nanoscale and controlling morphology in order to promote directional lithium ion diffusion. The direct continuous flow hydrothermal synthesis of lithium iron phosphate leads to spherical and diamond-shaped particles of 100 – 500 nm diameters, while shape control has been achieved by the addition of an organic chelating agent leading to the formation of elongated nanoplates.
This work is all part of a large EU FP7 funded project called SHYMAN – Sustainable Hydrothermal Manufacturing of Nanomaterials.
Presentation: Invited oral at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, General Session 4, by Peter W. Dunne
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17
Submitted: 2013-06-20 09:06 Revised: 2013-07-17 10:35