Structural, morphological and optical properties of tungsten trioxide nanoparticle synthesis by pulsed laser ablation in water: effect of laser fluence

In this paper, we introduce the pulsed laser ablation in liquid technique for the synthesis of tungsten oxide nanoparticle colloid in water. Tungsten trioxide nanoparticles produced at different laser fluence in DD water at room temperature by pulsed laser ablation of the W target have been studied. The effect of increasing laser fluence on the structural, morphological and optical properties of WO 3 NPs was investigated by using X-ray diffraction (XRD), optical properties, photoluminescence (PL), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy and transmission electron microscopy (TEM). The XRD data demonstrated that all of the produced WO 3 NPs are polycrystalline and confirm producing WO 3 NPs in all samples at water environments. The absorption spectra of all samples contained the excitonic/plasmonic absorption peak of WO 3 NPs. Direct optical energy gap of WO 3 NPs prepared at different laser fluence was in the range of 3.02–3.1 eV at room temperature. The PL measurement indicates a peak emission centered at 404 nm, and increasing the laser fluence results in a redshift. The PL spectra showed band-to-band transitions and WO 3 oxygen vacancies. The surface morphology of WO 3 NPs investigated by FESEM revealed the formation of spherical NPs morphologies, and the TEM result shows the particle size and concentration of wo3 increased from 6 to 33 nm with increasing laser fluence. The goal of this experiment was to demonstrate how the laser fluence might be used to regulate the concentering of WO 3 nanoparticles. In other words, laser fluence are a helpful tool for managing the concentering and particle size of created WO 3 nanoparticles.