Customization of structure, morphology and optical characteristics of silver and copper nanoparticles: Role of laser fluence tuning

Production of high purity silver (Ag) and copper (Cu) nanoparticles (NPs) with desired physical properties remains challenging. Thus, pulsed laser ablation in liquid (PLAL) method was used to prepare spherical AgNPs and CuNPs in deionized water (DIW) at various laser fluencies (LFs) (2.83-14.15 J cm-2). The structures, morphologies and optical behavior of these NPs as a function of varying LFs were determined. UV-Vis absorbance of these NPs was gradually increased accompanied by a blue shift. The optical band gap energy of AgNPs and CuNPs were in the range of 2.66-2.79 eV and 3.14-3.44 eV, respectively, wherein ATR-IR spectra confirmed their high purity. TEM and HRTEM images displayed the nucleation of spherical, homogenous, and crystalline AgNPs and CuNPs with corresponding mean diameter ranged from 8.1 to 32.5 nm and 6.2-33.1 nm. It is asserted that the obtained pure and spherical AgNPs and CuNPs with customized properties may be beneficial for photovoltaic and photocatalytic applications.