Generation of nanomaterials in dopant-containing liquid via pulsed laser ablation

Abstract

Nanoparticles of ZnS doped with Cu were prepared by means of pulsed laser ablation in liquid medium containing Cu ions. Nanosecond pulsed laser was focused on Zn target immersed in mercaptoethanol with copper nitrate dissolved as a source of Cu ions. X-ray diffraction and X-ray photoelectron spectroscopy confirmed formation of wurtzite ZnS structures as the main product, while up to ~5% of Zn atoms were substituted by Cu when ≤1.0 mM Cu(NO3)2 in mercaproethanol was used as liquid medium. Elemental mapping revealed that dopant Cu atoms were uniformly distributed in the produced nanoparticles. Photoluminescence recorded from the doped nanomaterial exhibited an additional green emission, indicating the presence of interband states resulted from doping with Cu2+. Compared with undoped ZnS nanoparticles, their Cu-doped counterparts demonstrated more efficient photocatalytic behavior toward the decomposition of methylene blue (as model organic compound), which is believed to be caused either by more efficient light absorption extended into the visible region or by the carriers based on the Cu2+ state. The present study demonstrates that the technique used has the capacity of producing doped nanomaterials in one step by incorporating dopants from the liquid phase, which may be promising for preparing novel unique nanomaterials with complex composition.