Facile laser-assisted synthesis of inorganic nanoparticles covered by a carbon shell with tunable luminescence

We report a one-step strategy at ambient conditions for the production of hybrid inorganic core-carbon shell nanoparticles by means of pulsed laser ablation of inorganic targets (LiNbO3, Au, and Si) in hydrocarbon liquids such as toluene and chloroform. The core of these spherical nanoparticles consists of the target material, whereas the shells are carbon structures (multilayer graphite-type carbon and amorphous carbon), which are formed due to the thermal decomposition of the organic liquid in contact with hot inorganic nanoparticles ejected from the bulk target. These carbon shells emit photoluminescence in the blue-green spectral region and the obtained luminescence, in which the luminescence band maximum position depends on the excitation wavelength, is analogous to the luminescence observed for the so-called carbon dots.