2D nanomaterials that could be used to create LEDs or solar cells.

19 July 2017

Radiant 2-dimensional carbon nitride nanomaterials

2-dimesional (2D) nanomaterials that could be used to create light emitting diodes (LEDs) or solar cells have been made through the simple, but unconventional, method of spontaneous dissolution.

This new industrially-scalable approach, published in Nano Letters, produces solutions containing fluorescent solutes that are defect-free, hexagonally-shaped 2d nanosheets (See Figure 1). The method is in stark contrast to the standard alternatives, which rely on on high energy input to delaminate layered materials, to produce meta-stable dispersions of fragments of 2d materials rather than pristine nanosheets.

The team from the Departments of Chemistry and Physics & Astronomy at UCL, the University of Bristol, Imperial College London and the École Polytechnique Fédérale de Lausanne, used advanced atomic force microscopy and transmission electron microscopy to investigate the structure 2D nanomaterials.

“Our method is surprising but incredibly simple. When we added certain solvents the layers of the carbon nitride simply floated off into solution. The process is very gentle so that the hexagonal shape of layers is maintained. Our high resolution TEM shows there are no visible defects across entire sheets.” said Dr Thomas Miller (UCL Chemistry).

In the study, funded by the European Union’s Graphene Flagship and the Engineering and Physical Sciences Research Council, the scientists showed that when these solutions were illuminated with UV light, they glowed (luminesced) with a distinctive colour. They went on to discover that this colour could be tuned by controlling the number of nanosheets stacked on top of one another.

“As we gain increased control over the dimensionality and functionality of carbon nitride nanomaterials we can begin to carefully tune their properties. This increases their potential for application in emerging technologies such as photocatalysis.” explained Prof. Paul McMillan (UCL Chemistry).

UCL Business PLC (UCLB), the technology commercialisation company of UCL has patented this research and will be supporting the commercialisation process.

For the full article, published in Nano Letters, please click on this link:  

‘Single Crystal, Luminescent Carbon Nitride Nanosheets Formed by Spontaneous Dissolution’ by Thomas S. Miller, Theo M. Suter, Andrew M. Telford, Loren Picco, Oliver D. Payton, Freddie Russell-Pavier, Patrick L. Cullen, Andrea Sella, Milo S. P. Shaffer, Jenny Nelson, Vasiliki Tileli, Paul F. McMillan and Christopher A. Howard

Figure 1. Hexagonal carbon nitride nanosheets gently dissolve into solution over time (left), producing luminescent, defect free 2d-nanosheets (right).