One-pot synthesis of graphitic and nitrogen-doped graphitic layers on nickel nanoparticles produced by pulsed laser ablation in liquid: Solvent as the carbon and nitrogen source

Abstract

Graphitic carbon (GC) and nitrogen-doped graphitic carbon (NdGC) shells have been synthesized on Ni nanoparticles (NPs) from solvents used in pulsed-laser ablation in liquid (PLAL). The facile one-pot synthesis was achieved at room temperature and atmospheric pressure by ablating the pulsed laser onto a Ni plate submerged in a solvent, which acted as the carbon and nitrogen source for the GC and NdGC shells. The formation of GC and NdGC shell-encapsulated Ni (Ni@GC and Ni@NdGC) NPs was simply and selectively achieved by selecting a specific solvent (hexane and acetonitrile), respectively. Meanwhile, Ni and Ni@NiO NPs were fabricated by pulsed-laser ablation in methanol and deionized water, respectively. The Ni NPs were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, fast Fourier transform analysis, selected area electron diffraction, and Raman spectroscopy. The Raman spectroscopic analysis revealed the graphitic shells were composed of well-organized graphitic structures. Furthermore, a potential application of the NPs as chemical shields in acidic conditions was tested in strong acidic solutions. The plausible growth mechanisms of various kinds of Ni NPs prepared by PLAL in different solvents are discussed.