Carbon dots (CD) are an emerging nanoscale material that has garnered attention because of their light absorbing and fluorescence properties.1 They exhibit strong, stable blue photoluminescence with diffuse absorbance in the UV and near visible region of the solar spectrum. CD consist of an amorphous carbon surface with a carbon core which is a mixture of nanocrystalline graphitic and amorphous carbon sites. These nanomaterials are usually around 2-10 nm in diameter, and are often considered quasi-spherical. They have been shown to be non-toxic and are considered biocompatible.2 Black phosphorus (BP), or phosphorene, is a metal-free 2-D direct band gap semi-conducting material that has recently garnered significant attention.3 It is composed of atomic layers of phosphorus that exists as a stack of two-dimensional puckered sheets that are held together by van der Waals forces (Figure 1b). BP nanomaterials are particularly intriguing as potential photosensitizers, because this material displays a layer dependent band gap. The bulk material has been shown to have a 0.3 eV band gap that increases with decreasing number of layers, up to 2.0 eV with a single atomic layer.4 This presents a big advantage; the bandgap of the material is tunable dependent on the thickness. BP nanomaterials can be easily made using liquid exfoliation of a bulk BP crystal using ultrasonication. Liquid exfoliation of BP has been reported in both organic4 and degassed-aqueous solutions.5 Our progress towards the synthesis, surface functionalization and doping of the CD and BPD nanoparticles and the effects these changes have on their photophysical properties will be presented. We hope to correlate the observed changes in photophysical properties with their effects on catalytic performance in a hybrid photocatalytic system.

Metal-free nanomaterials as photosensitizers for hybrid photocatalytic systems

256th National Meeting (2018)

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