title: Pulsed Laser Ablation-Induced Green Synthesis of TiO2Nanoparticles and Application of Novel Small Angle X-Ray Scattering Technique for Nanoparticle Size and Size Distribution Analysis.
abstract: This paper aims to introduce small angle X-ray scattering (SAXS) as a promising technique for measuring size and size distribution of TiO2nanoparticles. In this manuscript, pulsed laser ablation in liquids (PLAL) has been demonstrated as a quick and simple technique for synthesizing TiO2nanoparticles directly into deionized water as a suspension from titanium targets. Spherical TiO2nanoparticles with diameters in the range 4-35 nm were observed with transmission electron microscopy (TEM). X-ray diffraction (XRD) showed highly crystalline nanoparticles that comprised of two main photoactive phases of TiO2: anatase and rutile. However, presence of minor amounts of brookite was also reported. The traditional methods for nanoparticle size and size distribution analysis such as electron microscopy-based methods are time-consuming. In this study, we have proposed and validated SAXS as a promising method for characterization of laser-ablated TiO2nanoparticles for their size and size distribution by comparing SAXS- and TEM-measured nanoparticle size and size distribution. SAXS- and TEM-measured size distributions closely followed each other for each sample, and size distributions in both showed maxima at the same nanoparticle size. The SAXS-measured nanoparticle diameters were slightly larger than the respective diameters measured by TEM. This was because SAXS measures an agglomerate consisting of several particles as one big particle which slightly increased the mean diameter. TEM- and SAXS-measured mean diameters when plotted together showed similar trend in the variation in the size as the laser power was changed which along with extremely similar size distributions for TEM and SAXS validated the application of SAXS for size distribution measurement of the synthesized TiO2nanoparticles.
authors.affiliation: Department of Materials Science, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland. amandeep.singh@tut.fi.
authors.forename: Amandeep
authors.identifier: http://orcid.org/0000-0002-4087-6096
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Mechanical Engineering and Industrial Systems, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Vihinen
authors.affiliation: Department of Materials Science, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland.
authors.forename: Erkka
authors.initials: E
authors.lastname: Frankberg
authors.affiliation: Department of Materials Science, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland.
authors.forename: Leo
authors.initials: L
authors.lastname: Hyvärinen
authors.affiliation: Department of Materials Science, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland.
authors.forename: Mari
authors.initials: M
authors.lastname: Honkanen
authors.affiliation: Department of Materials Science, Tampere University of Technology, P. O. Box 589, FIN 33101, Tampere, Finland.
authors.forename: Erkki
authors.initials: E
authors.lastname: Levänen
keywords: Nanoparticle size and size distribution analysis; Nanoparticle synthesis; Nanoparticles; Pulsed laser ablation in liquids; SAXS; TEM; XRD