title: Structure and Optical Properties of Carbon Nanoparticles Generated by Laser Treatment of Graphite in Liquids.
abstract: In this paper, we report the one-step synthesis of luminescent carbon nanoparticles (NPs) via laser irradiation of a graphite target in a solvent [H2O, ethanol, or a 0.008 m aqueous diethylenetriaminepentaacetic acid (DTPA) solution]. This is a simple approach for the fabrication of carbon dots with tunable photoluminescence (PL) that differs from other preparation methods, as no post-passivation step is required. The unfocused beam of the second harmonic (wavelength 532 nm) of the Nd:YAG laser was used in our experiments. The sizes of the prepared NPs were mainly distributed in the range of 1-8 nm with an average value of 3 nm. Carbon NPs of different inner structure were prepared: hexagonal diamond phase in aqueous DTPA solution, orthorhombic carbon phase in ethanol, and amorphous carbon in water. The synthesized carbon NPs have strong luminescence in the visible region, which makes them attractive for numerous biological applications. The photoluminescence of the synthesized NPs was investigated at different excitation wavelengths, from 260 to 450 nm. The highest intensities of the emission bands were detected for an excitation wavelength of 400 nm.
authors.affiliation: B.I. Stepanov Institute of physics, National Academy of Sciences of Belarus, 68 Nezalezhnasti ave., 220072, Minsk, Belarus.
authors.forename: Natalie
authors.initials: N
authors.lastname: Tarasenka
authors.affiliation: B.I. Stepanov Institute of physics, National Academy of Sciences of Belarus, 68 Nezalezhnasti ave., 220072, Minsk, Belarus.
authors.forename: Aleksandr
authors.initials: A
authors.lastname: Stupak
authors.affiliation: B.I. Stepanov Institute of physics, National Academy of Sciences of Belarus, 68 Nezalezhnasti ave., 220072, Minsk, Belarus.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Tarasenko
authors.affiliation: Plasma Science and Nanoscale Engineering Group, Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University, Shore Road, BT37 0QB, Newtownabbey, UK.
authors.forename: Supriya
authors.initials: S
authors.lastname: Chakrabarti
authors.affiliation: Plasma Science and Nanoscale Engineering Group, Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University, Shore Road, BT37 0QB, Newtownabbey, UK.
authors.forename: Davide
authors.initials: D
authors.lastname: Mariotti
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D007834:Lasers; D049449:Luminescence; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D055620:Optical Phenomena; D004369:Pentetic Acid / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D000438:Alcohols; D012996:Solutions; D014867:Water; D002244:Carbon; D004369:Pentetic Acid
keywords: carbon dots; laser irradiation; nanoparticles; photoluminescence; structural defects