Resonant excitation of precursor molecules in improving the particle crystallinity, growthrate and optical limiting performance of carbon nano-onions

Abstract

A catalyst-free and highly efficient synthetic method for growing carbon nano-onions(CNOs) in open air has been developed through the laser resonant excitationof a precursor molecule, ethylene, in a combustion process. Highly concentricCNO particles with improved crystallinity were obtained at a laser wavelength of10.532 µm through the resonantexcitation of the CH2 wagging mode of the ethylene molecules. A higher growth rate up to2.1 g h − 1 was obtained, compared with that without a laser(1.3 g h − 1). Formation of the CNOs with ordered graphitic shells is ascribed tothe decomposition of polycyclic aromatic hydrocarbons (PAHs) intoC2 species. The optical limiting performances of the CNOs grownby the combustion processes were investigated. CNOs grown at10.532 µm laser excitation demonstrated improved optical limiting properties due to the improvedcrystallinity.