Optical, Structural, and Morphological Characterization of Titanium Oxide (TiO 2 ) Nanoparticles from Laser Ablation in Deionized Water

In this research, we focus on the synthesis of titanium oxide (TiO 2 ) nanoparticles using the Nd:Utilization of YAG laser pulse ablation technique in liquid environments, with pulse energies from 100 to 500 millijoules. The process employs a Nd:YAG laser operating at a frequency of 6 Hz and a wavelength of 1064 nm. (The TiO 2 nanoparticles synthesized in this study could be used in different high-temperature environments, as they are characterized by favorable physical, chemical, and mechanical properties). The synthesized product was further treated by calcination for four hours at temperatures higher than 600°C which promoted crystalline structure in the lattice. Comprehensive analyses were carried out to determine the nanoparticles' features. Optical features were studied through UV-visible spectroscopy to examine the absorption spectrum and band gap. The detailed examination of the crystal and surface structures was done using X-ray diffraction and field emission scanning electron microscopy (FE-SEM), in order to obtain insight into the structural integrity and the morphology of the titanium oxide nanoparticles. The study provides a deeper insight into TiO 2 nano particle production and their characteristics, thereby emphasizing their suitability for advanced material applications.


Introduction
Nanomaterials are increasingly being acknowledged as the key ingredient in most cutting-edge technologies and industries.This is because of the peculiarity in properties that can differ greatly from those of displayed by bulk materials [1].Properties such as size, shape, and surface-to-volume ratio supported by atomic structural differences influence directly the physical and chemical behaviours of nanoparticles, comprising electrical conductivity and energy band characteristics [2].Some of the nanoparticles that have received great interest are titanium oxide (TiO2) nanoparticles, especially in their use in many fields right from environmental remediation up to photocatalysis, medical applications, and energy solutions [3].One

Experimental
The experimental setup began with pristine metal sheets of titanium (Ti),

Optical properties
Absorbance for colloidal nanoparticles was assessed using UV-Vis Spectroscopy.NPs for different laser energies.

X-Ray Diffraction Analysis
The powder X-ray diffraction (XRD) analysis of TiO2 nanoparticles was of the areas of research focus for TiO2 nanoparticles has thus been their synthesis, since they have been environmentally friendly, low in toxicity, and show potential for application in green energy technologies [4].This process of obtaining these NPs usually involves the physical interaction of laser pulses with the titanium target to vaporize material, and then the nucleation and growth of NPs in a liquid medium [5].This highlights pulsed laser ablation in liquid (PLAL) as an attractive technique, since both energy input and environmental conditions are precisely controlled, giving rise to high-purity nanoparticles with the exact morphological and structural properties required for their application [6].This will set a stage in due course to discuss in detail the methodologies adopted for the synthesis of titanium oxide nanoparticles using PLAL, their resulting structural, optical, and morphological characteristics across the fields of many applications [7].It will put an emphasis on the benefits derived from using LA, such as being energy-efficient and low-cost, in order to produce nanoparticles which can suffice the harsh requirements for materials technology[8].

measuring 1 cm x 1
cm, characterized by a high purity level of 99.99%.The laboratory configuration, including the use of a highpurity titanium target and its specific composition, intended for pulsed beam irradiation.This apparatus comprises a Nd:YAG laser and a titanium (Ti) target assembly, submerged in deionized water.The titanium target, with a thickness of 2 mm, was mounted on a rotating device at the base of a glass container to prevent continuous ablation at a single point.The sample rotation facilitates even distribution of the laser influence.During the process, the target received 500 pulses from a Nd:YAG laser, emitting at a wavelength of 1064 nm.These pulses varied in energy from 100 to 500 mill joules and were delivered at a frequency of 6 Hz.The laser was positioned 12 cm away from the target to the focusing lens.The experimental protocol used a typical fluid volume of 3 mL of deionized water (DW).Subsequently, a colloidal solution of titanium oxide nanoparticles was synthesized.The resultant titanium oxide nanoparticles were preserved in the DW.
These nanoparticles were synthesized via Pulsed Laser Ablation in Liquids (PLAL) at a wavelength of 1064 nm, utilizing energies from 100 to 500 mJ in a medium of deionized distilled water, and subsequently analyzed in a quartz cuvette with deionized water as the reference.It's important to highlight that the particle size of nanomaterials significantly influences their electronic structure, particularly affecting the energy levels of electrons and holes in the conduction and valence bands.Consequently, the absorption and optical emissions of the nanomaterials are dependent on these energy levels.Specifically, absorbance was measured for five TiO2 nanomaterial samples, prepared using an Nd:YAG laser ablation at varied energies (100, 200, 300, 400, and 500 mJ) operating at a frequency of 6 Hz.The absorbance range for these samples was diagnosed using the UV-Vis Spectroscopy.

Figure 1
Figure 1 shows the absorbance of titanium oxide, which is within the range of low wavelengths with high energy a blue colour from 200 nm to 350 nm.This practical result comes in agreement with the size of nanoparticles of titanium oxide in previous studies and the phenomenon in electron microscopy examinations [9].

Figure 1 :
Figure 1: UV-Visible absorbance of synthesiz TiO2 NPs using different laser energies.Moreover, figure 2 illustrates the optical energy gaps for titanium oxide, starting at

Figure 2 :
Figure 2: Optical energy gap of TiO2 diffractometer equipped with CuKα radiation (wavelength = 0.15406 nm) to determine the crystal structure.The crystallite size, an important parameter in nanoparticle characterization, was calculated using the Scherrer formula from the full width at half maximum (FWHM) of the most intense peak.This calculation yielded an average crystallite size of 29.35 nm.The crystallite size is crucial for understanding the material's properties, as it can influence the chemical reactivity, mechanical properties, and electronic behaviour of the nanoparticles.The XRD patterns are shown in Figure 3 that verifies the presence of the tetragonal crystal phase of titanium dioxide, specifically the Anatase form, as it lacks any peaks indicative of impurities.Distinct reflection peaks were observed and labeled according to their corresponding Miller indices: (222), (400), (440), and (622), which are typical for TiO2 diffraction planes.The average crystallite size calculated from the most intense peak was determined to be 29.35nm [10].