Improved Laser Ablation Method for the Production of Luminescent Carbon Particles in Liquids

Abstract

An improved method for the production of luminescent carbon nanoparticles is proposed in this work. The new method overcomes the disadvantages of commonly used approaches. It involves two-stage laser ablation in water and in aqueous solutions, where the first stage is the laser ablation of a graphite target and the second is the shredding of particles produced in the first step. The two-stage method offers the optimization of the laser pulse fluence for the performance of each process. It was found that the two-stage process of laser ablation allows producing photoluminescent carbon structures in pure water. The additional reagent may be added either in the first or second stage. The first stage performed in pure water allows avoiding the contamination of the target. Moreover, it simplifies the identification of the origin of photoluminescence. Two synthesis routes for the preparation of carbon nanoparticles by the proposed method using pure water as well as urea aqueous solution are investigated. It was found that the use of urea as a reagent results in luminescence properties similar to those obtained with other more hazardous amine-based reagents. The influence of the synthesis approach and process parameters on the structural and luminescent properties of nanoparticles is also explored in this work.

Graphene Nanostructures by Pulsed Laser Ablation in Liquids: A Review

“…To improve the production of luminescent carbon nanoparticles, a two-stage PLAL process was suggested [ 115 ]. In the first stage, an unfocused laser beam of 1064 nm wavelength was made to fall on a graphite target submerged in a liquid.…”

“…Splitting the process into two stages helped meet the conflicting requirements, in terms of fluence, for the ablation and refinement of the fabricated particles. Incorporating urea in stage one or two or both helped in improving the luminescent properties of the CNPs [ 115 ].…”

The Luminescence of Laser-Produced Carbon Nanodots: The Effect of Aggregation in PEI Solution

“…Even though pulsed laser ablation in liquids (PLALs) is perceived as an alternative to chemical syntheses, owing to limiting the amount of the reagent used, the presence of fluorophores cannot be excluded. This is due to the interactions between the laser beam and the surrounding liquid during the ablation process [10,18]. Hence, the source of the luminescence of the obtained CND complexes remains disputable.…”