10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Optical and Electronic Properties of Flame-Synthesized Carbon Nanoparticles

CHIARA SAGGESE, Ajay V. Singh, Lucy Kaye, Hai Wang, Stanford University

     Abstract Number: 1417
     Working Group: Combustion-Generated Aerosols: the Desirable and Undesirable

Abstract
Combustion-generated aerosol (soot) or smoke is a notorious air pollutant with hazardous effects on human health and wide-ranging impacts on regional and global climate. Nevertheless, it was only recognized very recently that nascent flame soot particles, i.e., those intercepted during early stages of formation, exhibit fascinating optical and electronic properties, which can be exploited for potential applications in energy conversion and medical diagnostic [1, 2].

In this work, carbon nanoparticles (CNPs) with sizes around 10 nm are synthesized using a series of laminar premixed burner-stabilized stagnation flames [3] and CNPs properties are characterized through UV-visible absorption spectroscopy and fluorescence spectroscopy.

CNPs are collected thermophoretically onto quartz slides at various distances from the burner surface. UV-visible absorption spectra of the particle samples are collected and analyzed in terms of Tauc optical bandgap thus allowing a quantification of the apparent optical bandgap for as-synthesized particles. The results demonstrate the dependency of the optical bandgap on particle size. Fluorescence is observed in the wavelength range of 400-650 nm from particles suspended in organic solvents. Analysis of fluorescence excitation-dependency is carried out and the influence of the solvent is investigated. Implications of these findings will be discussed.

[1] Z. Wei, K. Yan, H. Chen, Y. Yi, T. Zhang, X. Long, J. Li, L. Zhang, J. Wang, S. Yang, Energy & Environ. Sci. 7(10) (2014) 3326-33.
[2] H. Liu, T. Ye and C. Mao, Angew. Chem. 46 (2007) 6473-75.
[3] J. Camacho, C. Liu, C. Gu, H. Lin, Z. Huang, Q. Tang, X. You, C. Saggese, Y. Li, H. Jung, L. Deng, I. Wlokas, H. Wang, Combust. Flame 162 (2015) 3810-3822.