ZnO@graphene oxide core@shell nanoparticles prepared via one-pot approach based on laser ablation in water

Core-shell nanoparticles (NPs) have attracted tremendous attention due to their tunable properties and numerous potential applications. However, preparation of uniform and size-controlled core-shell nanomaterials of ZnO with graphene oxide (GO) is still considered as a challenging task even after years of research. In this work, we report on a facile one-pot organics-free method for preparation of GO-wrapped ZnO NPs. Laser ablation of zinc and carbon targets in water medium at ambient atmosphere resulted in formation of spherical ZnO core and GO shell, respectively. According to Raman active modes, the GO shell was layered and the ZnO core was polycrystalline. Both Raman spectra and X-ray diffraction patterns revealed that formation of layered GO increased stress inside the ZnO core. Surface layers reduced the density of defects and disorders in the ZnO crystal lattice and enhanced the phonon lifetime. Also, the minimal interfacial disorder between the layered GO and ZnO core resulted in continuous formation of a GO layer. Thus, laser ablation in liquid is demonstrated to provide stable and uniform core-shell GO@ZnO NPs with controlled GO layer that can find applications in biomedical and sensing fields.