MRI SEMINAR -Dr. Tom S Miller, University College London - Nanosheets Formed by Spontaneous Dissolution: Single Crystal, Luminescent Carbon Nitrides and more
Date: 18 October 2017 Time: 15:00 - 16:00
Graphitic carbon nitrides have been under intense investigation during the last decade due to their unique semiconducting, optoelectronic and catalytic properties. This has led to their development as an important class of materials for applications including light harvesting for photocatalysis and photovoltaics. Two-dimensional (2D) carbon nitrides have already been shown to have enhanced performance, but the methods used to produce these and other nanomaterials are usually unscalable and detrimentally alter the physical and chemical properties of the nanosheets.
A primary method for the production of 2D nanosheets is liquid-phase delamination from their 3D layered bulk analogues. Most strategies currently achieve this through structurally damaging mechanical energy input or chemical modification. Here I will present our recent work in which we demonstrate the true dissolution of a wide range of 2D nanomaterials, including the poly(triazine imide) (PTI) form of carbon nitride. This semiconductor is spontaneously soluble in select polar solvents. Our thermodynamically-driven dissolution process perfectly maintains the crystallographic form of the starting material, yielding solutions of defect-free, hexagonal 2D nanosheets. This pristine nanosheet structure results in narrow, excitation-wavelength-independent photoluminescence emission spectra. By controlling the aggregation state of the nanosheets, we demonstrate that the emission wavelengths can be tuned from narrow UV to broad-band white. This has potential applicability to a range of optoelectronic devices.
Thomas S. Miller currently works in the Dept. of Chemical Engineering at UCL. He received his MChem (2009) and PhD (2014) at the University of Warwick, where he studied electrochemical applications of carbon nanomaterials.
His research interests span from fundamental electrochemistry to materials discovery/characterisation and the development of devices for electrochemical energy storage/generation. In his recent work he has produced new methods for the scalable production of 2D materials and created carbon nitride composites for application in fuel cells, batteries, electrolyzers and supercapacitors
|Location:||David Sizer Theatre|