Effect of Temperature Sintering on Grain Growth and Optical Properties of TiO<sub>2</sub> Nanoparticles

Tsega Yihunie, Moges

doi:https://doi.org/10.1155/2023/3098452

Journal of Nanomaterials

On this page

Abstract Introduction Results and Discussion Conclusion Data Availability Additional Points Conflicts of Interest References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 3098452 | https://doi.org/10.1155/2023/3098452

Effect of Temperature Sintering on Grain Growth and Optical Properties of TiO₂ Nanoparticles

Moges Tsega Yihunie¹

Academic Editor: Rajalakshmanan Eswaramoorthy

Received29 Jul 2022

Revised12 Feb 2023

Accepted14 Feb 2023

Published11 Apr 2023

Abstract

Titanium dioxide (TiO₂) nanoparticles were prepared by the sol–gel method and the structural, morphological, and optical properties were investigated at different sintering temperatures of 500, 600, 700, 800, and 900°C. A tetragonal structure of anatase, mixed (anatase–rutile), and rutile phases are observed in the X-ray diffraction (XRD) analysis. Pure anatase phase formation occurred at 500°C, whereas anatase-to-rutile phase transformation began at 600°C, and reaching complete conversion to rutile at 800°C. The average crystallite size increased from 23 to 34 nm for anatase and 38 to 62 nm for the rutile when sintering temperature increased from 500 to 900°C. The scanning electron microscope (SEM) result presented the increase of grain size (25–100 nm) with increasing the sintering temperature. The Fourier transform infrared (FTIR) spectra demonstrated the presence of TiO₂ vibrational bonds in all samples. The optical bandgaps of the sintered TiO₂ nanoparticles decreased with rising sintering temperature. Photoluminescence spectra exhibited three characteristic peaks centered at 380, 450, and 550 nm. The emission intensity increased with increasing the sintering temperature. The Mie analysis was also studied to calculate scattering cross-section, forward scattering, and asymmetry for different grain sizes. The results showed that by increasing the nanoparticle diameters, the peaks of all spectra are redshifted for larger grain sizes and cross-section peaks shift to high values. In this study, the sintering temperature is observed to have a strong influence on crystalline phase transformation, microstructure, and optical properties of TiO₂ nanoparticles. The TiO₂ sample sintered at 900°C shows the best result to be used as luminescent material due to the low optical bandgap energy.

1. Introduction

Titanium dioxide (TiO₂) is a cheap, nontoxic, and nonbiodegradable material possessing many unique physical, chemical, and optical properties. Recently, nanostructured TiO₂ has attracted considerable attention because of its potential application in photocatalysis, gas sensors, solar cells, and lithium-ion batteries [1–3]. TiO₂ occurs naturally in three different crystalline phases: anatase, rutile, and brookite. Anatase and rutile are tetragonal, whereas brookite belongs to the orthorhombic crystalline system [4]. Each crystalline phase has different bandgaps that consist of different oriented TiO₆ octahedral chains [5]. Under ambient conditions, rutile is thermodynamically stable, whereas anatase and brookite are thermodynamically metastable. The anatase phase of TiO₂ is more effective as photocatalyst under UV light than rutile and brookite. However, its large bandgap (∼3.2 eV) does not enable it to absorb light in the visible region. In comparison, the rutile phase of the TiO₂ was employed majorly in areas that involve high-end optics and electronics because of its high dielectric constant [6].

Several methods have been used by researchers to synthesize TiO₂ nanoparticles such as chemical precipitation [7], combustion [8], sol–gel [9, 10], and hydrothermal methods [11]. Among these methods, the sol–gel method is a simple process to synthesis TiO₂ nanoparticles. The sol–gel synthesis provides high purity, homogeneity, and high control over morphology and crystalline phases [12]. Different parameters such as precursor type, initial solution, pH, and heating temperatures affect the sol–gel synthesized powders [13, 14]. The different phases of TiO₂ nanoparticles can be obtained or maintained by controlling their temperature [15, 16]. The anatase-to-rutile phase transformation significantly depends on the annealing time and annealing temperature [17]. Annealing modifies the crystal structure and, hence, the microstructural and morphological properties of TiO₂ [18–20]. The sintering temperature also results in a change of micrograin structure, crystallinity, morphology, grain size, etc. [21–24]. Dhiflaoui et al. [25] synthesized pure rutile TiO₂ nanoparticles after heating at 850°C. On the other hand, Bakri et al. [26] suggested that anatase/rutile phase transformation occurred at temperature >900°C.

In recent years, there has been an increasing interest in the study of optical scattering and absorption of TiO₂ nanoparticles using theoretical simulations. Despite the large amount of work on the synthesis, experimental characterization, and property measurements of TiO₂ nanoparticles, the number of reports with theoretical simulations is still quite limited [27, 28]. When the size of the particles becomes smaller, novel optical characteristics emerge [29]. The Mie analysis is one of the related computational methods used for studying the optical scattering and absorption properties. The Mie theory has the advantage of being conceptually simple and has found wide applicability in explaining experimental results. Theoretical calculations for the scattering coefficients depending on nanoparticle size were made using Mie calculations [30, 31]. In this work, the influence of different sintering temperatures (500, 600, 700, 800, and 900°C) on the phase transformation, crystallite size, surface morphology, and optical properties of TiO₂ nanoparticles prepared by sol–gel method was studied. Moreover, the Mie analysis was studied for different particle sizes of nanoparticles and scattering cross-section, forward scattering, and asymmetry were calculated.

2. Experimental Methods

Nanosized TiO₂ powder was synthesized via a sol–gel method using tetra-n-butyl orthotitanate (C₁₆H₃₆O₄Ti) (Sigma–Aldrich) as the titanium precursor, ethylenediamine (C₂H₈N₂) (Sigma–Aldrich) as the catalyst, and ethanol (C₂H₅OH) (Sigma–Aldrich) and deionized water (H₂O) as the solvent. In a typical experiment, 10 ml of tetra-n-butyl orthotitanate was added dropwise into 40 ml of ethanol and stirred for 2 hr. Deionized water was added to the mixture followed by the addition of ethylenediamine under vigorous stirring. The solutions were placed in the fume hood to chill for about 3–4 days where the milky gel was obtained. The obtained gel samples were then sintered in a muffle furnace at 500, 600, 700, 800, and 900°C for 1 hr and naturally cooled down to the room temperature.

X-ray diffraction (XRD) patterns of TiO₂ were measured using Bruker D8 X-ray diffractometer with Cu Kα radiation (λ = 1.5406 Å), with scattering angle of 20°–80°. The surface morphology of the samples was obtained with a field-emission scanning electron microscope (FE-SEM) (ZU SSX-550, Shimadzu). An energy-dispersive X-ray spectroscopy (EDS) spectrum was obtained by attaching to a SEM for elemental analysis. Fourier transform infrared (FTIR) (PerkinElmer STA 600 model) spectrometer was used to examine the synthesized nanoparticle’s functional group using KBr. The reflectance spectra of the TiO₂ nanoparticles were measured using a PerkinElmer Lambda 950 UV–Vis photospectrometer. Photoluminescence (PL) spectra of the samples were measured at room temperature by using a Cary Eclipse fluorescence spectrophotometer (model LS 55) with a built-in 150 W xenon lamp as the excitation source and a grating to select a suitable wavelength for excitation.

3. Results and Discussion

Figure 1 shows the XRD patterns of the TiO₂ samples sintered at different temperatures (500, 600, 700, 800, and 900°C) for 1 hr. The sample sintered at 500°C was identified as nanocrystalline anatase phase and intense peak corresponding to (101) plane (Figure 1(a)). This phase formation is agreed with that obtained by Delekar et al. [32]. The major XRD diffraction peaks can be attributed to (101), (004), (200), (105), (211), (204), and (215) plane of anatase phase (JCPDS 84-1286) with tetragonal structure. More increased sintering temperature also causes phase transition from anatase to rutile. The rutile peaks appearing after sintering at 600°C indicate that phase transformation from anatase to rutile has occurred (Figure 1(b)). The rutile peaks become intense as the temperature increased to 700°C (Figure 1(c)). A complete transformation into rutile was occurred at 800°C (Figure 1(d)). Further increase to 900°C, the intensity of the (110) rutile orientation was also increased (Figure 1(e)) [15]. The rutile diffraction peaks correspond to the (110), (101), (200), (111), (210), (211), (220), (002), (310), and (301) tetragonal crystal planes which well matched with JCPDS file 76-318. Similar results have been reported in the literature [18, 33]. Arroyo et al. [34] reported that the transformation from anatase to rutile occurs above 800°C for pure TiO₂ materials. Zhang and Tang [35], however, reported that the complete transformation from anatase to rutile occurs above 900°C. It is noticed that intensity of the rutile diffraction peaks increases with increase in the sintering temperature, showing the degree of crystallinity of the nanopowders [36, 37].

The percentage of respective peaks corresponding to different phases is calculated by using the Spurr equation [38]:where I_A and I_R are peak intensities for (101) plane of anatase and (110) plane of rutile phases, respectively. The crystallite sizes (D) of the anatase and rutile phases are calculated by using the Scherrer equation [39]:where D is the crystallite size, λ is the X-ray wavelength, β is the full width at half maximum (FWHM) (in radian), and θ is the Bragg’s diffraction angle. The average calculated crystallite size and phase composition of TiO₂ nanoparticles prepared at different sintering temperatures are presented in Table 1. At 600°C, the phase components were 78% for anatase and 22% for rutile. At 700°C, the percentages of anatase and rutile phases were also found to be 14% and 86%, respectively. Similar result has been reported in the literature [13]. A complete transformation from anatase to rutile phase was occurred at 800°C. It can be seen that with increasing sintering temperature to 700°C, the size of anatase phase crystallite increases from 23 to 34 nm. The crystallite size of rutile phase increased with increasing sintering temperature, with values of 38, 42, 49, and 62 nm at 600, 700, 800, and 900°C, respectively. The increase in crystallite size with increasing heating temperature may be attributed due to thermally promoted crystal growth. Anatase nanocrystallites having small size and high concentration of defects easily undergo phase transformation to rutile [40]. This result showed that the sintering temperature has a significant effect on the phase transformation, crystallite size, and crystallinity of TiO₂ nanoparticles.

Figure 2 shows the SEM image of TiO₂ nanoparticles sintered at 500, 600, 700, 800, and 900°C for 1 hr. Sample sintered at 500°C (Figure 2(a)) showed nonspherical small grains with a grain size of about 25 nm. As the sintering temperature increased to 600°C, the sizes became bigger with a grain size of about 35 nm, as shown in Figure 2(b). With increase in temperature to 700°C (Figure 2(c)), the sample showed well-defined near-spherical-shaped particles that are evolved into a clear and dense shape particle with grain sizes of about 50 nm. As further increase in temperature up to 800 (Figure 2(d)) and 900°C (Figure 2(e)), TiO₂ nanoparticles exhibited nonuniform shape of particles due to the agglomeration of initial particles with increase in grain size ranging from 80 to 100 nm. Grain boundaries can be clearly identified and a trend that the grain growth continued with the increase in the heating temperature was observed. Ostwald ripening at high temperatures leads to more nucleation of the nanoclusters and more growth [13, 17, 41]. Further, the sintering at 900°C (Figure 2(e)) showed large grain sizes of about 100 nm and showed a high degree of agglomeration [17]. The degree of agglomeration of TiO₂ nanoparticles is due to the adhesion of nanoparticles to each other and diffused boundaries [38, 42]. Moreover, the spherical morphology of the particles disappeared [17], indicating the crystal growth of titania with better densification. It is possible that some big particles with smooth interface embedded in the small crystallites forming large grains. At the highest calcination temperature, the particles and pores undergo melting-like process so that the coarsening rate for rutile will be significantly greater than that of anatase [43]. The increase in grain sizes due to aggregation of nanoparticles with the increased sintering temperature in the SEM patterns indicates increased crystallinity. The SEM results are in agreement with XRD results that showed the grain size of the anatase phase smaller than rutile phase due to aggregation of nanoparticles with increased sintering temperature. Similar results have been reported in other studies [17, 23, 44]. The histogram of particle size distribution of the TiO₂ nanoparticles sintered at 800 and 900°C was analyzed by using ImageJ software. The average grain size was estimated to be around 83 nm at 800°C (Figure 2(f)) and 90 nm at 900°C (Figure 2(g)). These values are close to the grain size estimated in the SEM images. It is clearly seen that the sintering temperature influences the morphology and size of the nanoparticles.

Figures 3(a) and 3(b) show the EDS spectrum of TiO₂ nanoparticles sintered at 800 and 900°C, respectively. The spectra have prominent peaks of titanium (Ti) and oxygen (O). No impurities were present. Atomic percentages of O decreased from 61.38 (51.52 wt%) to 56.18 (46.15 wt%) and Ti increased from 38.62 (48.48 wt%) to 43.82 (53.85 wt%), as the sintering temperature increased from 800 to 900°C. The O value is far below for the required theoretical atomic percentage of 66.67. The lower oxygen content could be attributed to the point defect in the form of oxygen vacancy in TiO₂ crystals at higher temperature.

(a)

(b)

Figure 4 shows the FTIR spectra of the sol–gel-driven TiO₂ nanoparticles sintered at 500–900°C for 1 hr. The bands around 3,401 and 2,959 cm⁻¹ are assigned to the stretching vibrations of adsorbed water and hydrogen-bonded hydroxyl groups [45]. The broad peak observed at 2,425 cm⁻¹ may correspond to the C–H stretching of hydrocarbon bonds. The bands at 2,050 and 1,950 cm⁻¹ can be attributed to the vibrations of the C=O bonds in TiO₂ matrix. The peak at 1,650 cm⁻¹ in the spectra is related to the stretching and bending vibrations of the Ti–OH and the –OH group of TiO₂ nanoparticles [41]. The absorption band observed in the range of 400–800 cm⁻¹ is the contribution from anatase titania. The peak at about 500 cm⁻¹ can be attributed to the vibration of Ti–O bond in TiO₂ lattice [33, 46]. The absorption band at 730 cm⁻¹ can be assigned to the Ti–O–Ti stretching vibrations [47]. The intensity of lower absorption bands decreased with the increase of the sintering temperature, indicating the removal of water molecules from the samples [48, 49]. For sintering above 800°C, additional intense absorption bands of exothermic peaks are observed. The exothermic peak can be associated with the crystallization of rutile TiO₂ [50]. Increase in sintering temperature results in the increase in crystallite size, thereby decreasing the surface area for adsorption of water.

The optical reflectance spectra of the as-prepared TiO₂ nanoparticles sintered at 500, 700, and 900°C were recorded at room temperature and shown in Figure 5(a). With the increase of sintering temperature, the absorption edge is observed to be shifted toward the higher wavelength with a redshift [51]. This is due to increase in crystallite size and the induced oxygen vacancy (defect sites) at higher sintering temperature. Figure 5(b) indicates bandgap plot calculated via Tauc equation for the corresponding samples. The reflectance data were converted to the absorption coefficient α values according to the Kubelka–Munk equation [52]:where α is the absorption coefficient and R is the reflectance. The absorption coefficient α and the bandgap E_g are related through the Tauc equation [53]:where hν is the photon energy, A is a proportionality constant, and n = 1/2 is indirect bandgap transition. The optical bandgap energy can be calculated by plotting the graph of (αhν)^1/2 vs. hν and extrapolating the linear section of the curve to the hν axis. The calculated bandgap values are 3.3, 3.2, and 3.1 eV corresponding to the samples sintered at temperature of 500, 700, and 900°C, respectively. The bandgap obtained at 500°C is larger than the bandgap of rutile TiO₂ sintered at 900°C. This trend is due to the phase transformation from anatase to rutile as clearly evident from XRD pattern [46]. At higher sintering temperature, growth of favored particles and agglomerates correspond to decrease in bandgap energy. This can be accounted as a result of increase in size of the crystallites by agglomeration at higher temperature [15, 24]. Hence, the reduced bandgap energies at raised sintering temperatures confirm the increase in grains as observed in SEM images. The narrowing of bandgap is prescribed to generation of new energy states in forbidden energy band of TiO₂ supporting photogeneration [54]. Similar results have been reported [15, 33].

(a)

(b)

Figure 6 shows the room temperature photoluminescence (PL) spectra of the sintered TiO₂ samples at 500, 600, 700, 800, and 900°C for 1 hr when excited at 320 nm. The PL peak positions that observed for anatase and rutile samples are similar, but relative intensities of these peaks are different. All samples exhibited broad emission peaks near 340–550 nm centered at 380, 470, and 550 nm. The observed broad and intense emission peaks originate from the recombination of exciton. The sample sintered at 500°C possesses the lowest PL intensity, revealing that the photogenerated holes and electrons have the lowest recombination rate in the sample. Samples sintered above 500°C induced an increase in the emission peaks. The UV emission band at 380 nm can be attributed to the indirect band-to-band transition from conduction band to valence band of TiO₂ nanoparticles [55]. The peaks observed at 470 and 550 nm are due to the self-trapped excitons, oxygen vacancies, and surface defects of TiO₂ [19, 56]. The PL intensity is a direct indicator for the charge recombination rate, i.e., stronger the PL intensity, higher the recombination rate and vice versa. The PL emission from sample sintered at 900°C is higher compared to the sample sintered at 500°C. Moreover, the increase in PL intensity for samples sintered at 600, 700, 800, and 900°C indicates the presence of mixed phases of anatase–rutile and pure rutile. This is also correlated that the increase in sintering temperature leads to the increase in the size of TiO₂ nanoparticles as observed in XRD and SEM investigations. By comparing the PL spectra of the TiO₂ samples sintered at 600, 700, and 800°C with that of the TiO₂ samples sintered at 900°C, it is clearly seen that the defect-related emission band at 530 nm is largely enhanced, while the blue emission at 470 nm is slightly suppressed. This can be attributed to the aggregation and rutile phase formation at elevated temperature, leading to an increased recombination process. At high sintering temperature, most of the nonradiative centers are covered up; however, thermally generated radiative oxygen vacancies become dominant defects in the TiO₂ lattice [56–58].

The Mie theory was used to calculate the optical parameters like scattering cross-section (C_sca), backscattering (Q_rad), and asymmetry (g). All waves incident on a particle are either absorbed or scattered. The scattering cross-section of a particle is the amount of light scattered by the particle relative to the light intercepted by its physical cross-section. The Mie solution, according to Maxwell’s equations [59], describes the scattering of a plane wave by a particle and is given by:where k = 2π/λ is the wavenumber and a_n and b_n are the Mie coefficients. Furthermore, the asymmetry parameter g indicates the average cosine of the scattering angle θ with respect to incident wavelength and is given by:

Assuming that the index of refraction of TiO₂ is n = 2.5 and the incident radiation is λ = 320 nm. Theoretical assessments of the scattering peak depending on nanoparticle size were made using Mie calculations, performed with software “Mie Plot v.4.3.” Figure 7(a) shows the scattering cross-section of TiO₂ nanoparticles at different grain sizes (diameter = 25, 35, 50, 100, and 150 nm). It can be seen that the scattering cross-section peak is increased with increasing grain sizes, as shown in Figure 7(b). The numerical results showed that the scattering properties of nanoparticles with small particles vary smoothly with wavelength, while the scattering properties of nanoparticles with large particles oscillate with wavelength due to diffraction peaks. Moreover, the peak of all spectra is redshifted for larger particles. A redshifting of the scattering peak is expected for interparticle spacing of the order of the particle diameter [60]. Figure 7(c) shows the forward scattering of TiO₂ nanoparticles at the grain size of 25–150 nm. For nanoparticles with small grain sizes (25–50 nm), the forward scattering is increased slowly. However, the forward scattering is increased rapidly with the increase in grain size from 100 to 150 nm. For particles of 100 nm, an increase in the forward scattering is clearly visible, thus the scattering is asymmetric. With increasing particle size, the forward scattering becomes more pronounced, causing a larger asymmetry parameter, as shown in Figure 7(d). This is in agreement with the behavior of nonabsorbing systems [29].

(a)

(b)

(c)

(d)

4. Conclusion

Nanocrystalline TiO₂ particles were prepared by the sol–gel method sintered at 500, 600, 700, 800, and 900°C for 1 hr. The XRD results showed that only tetragonal anatase phase is achieved at 500°C. A phase change occurs from anatase to mixed (anatase–rutile) to rutile with varying sintering temperatures. At 600°C, the phase transition from anatase to anatase–rutile mixed phase is noticed. The transformation from mixed phase to pure rutile was completed at 800°C. The average crystallite size of TiO₂ nanoparticles sintered at 500–900°C is found to lie in the range of 23–34 nm for anatase phase and 38–62 nm for rutile phase. The SEM results revealed an increase in grain size from 25 to 100 nm with increasing the calcination temperature from 500 to 900°C. At 900°C, the sample showed a bigger grain size of about 100 nm with clear grain structure and better densification. The stretching vibrational mode corresponds to anatase and rutile phases is explained by FTIR spectra of TiO₂ nanoparticles. From UV–Vis analysis, the bandgap of TiO₂ decreased from 3.3 to 3.1 eV with increasing sintering temperature from 500 to 900°C. The optical reflection study reveals that the reflection band edge shifts toward longer wavelength with increase of sintering temperature. The PL analysis shows the existence of both UV and visible emissions. A broad PL emission band from 350 to 550 nm is seen in all samples. Three characteristic peaks centered at 380, 450, and 550 nm were found. Further, PL spectroscopy revealed the change in emission intensity with sintering temperature and is in accordance with indirect transition. These defect-related emissions can be associated with the enhanced formation of surface defects and oxygen vacancies in the TiO₂ structure. The Mie analysis was studied and TiO₂ nanoparticles with different diameters were considered to investigate the correlation between the grain size and optical cross-section values. The results showed that by increasing the nanoparticle diameters, the peaks of all spectra are redshifted for larger grain sizes and cross-section peaks shift to high values. In this study, the sintering temperature is observed to be a key factor for the tuning of TiO₂ crystallite size, bandgap, and the phase transition.

Data Availability

The underlying data supporting the results of this study are found in the results and discussion part.

Additional Points

Highlights. Sol–gel-derived TiO₂ nanoparticles are studied for their phase transformation. The melting-like process accelerates the phase transition from anatase to rutile. The optical bandgaps of the sintered TiO₂ nanoparticles decreased with rising sintering temperature. The PL intensity and grain size increased with increasing sintering temperature. Redshifted and high scattering values for larger grain sizes were calculated. The suitability of Mie theory was estimated with scattering parameters.

Conflicts of Interest

The author declares that there is no conflicts of interest.

Funding

The authors acknowledge the financial support by the University of the Free State, Tertiary Education Support Program (ESKOM), and Organization of Protection of the Chemical Weapon (OPCW).

References

C.-S. Chou, C.-Y. Chen, S.-H. Lin, W.-H. Lu, and P. Wu, “Preparation of TiO₂/bamboo-charcoal-powder composite particles and their applications in dye-sensitized solar cells,” Advanced Powder Technology, vol. 26, no. 3, pp. 711–717, 2015.
View at: Publisher Site | Google Scholar
L. Huang, T. Liu, H. Zhang, W. W. Guo, and W. Zeng, “Hydrothermal synthesis of different TiO₂ nanostructures: structure, growth and gas sensor properties,” Journal of Materials Science: Materials in Electronics, vol. 23, pp. 2024–2029, 2012.
View at: Publisher Site | Google Scholar
M. Zukalova, J. Prochazka, Z. Bastl et al., “Facile conversion of electrospun TiO₂ into titanium nitride/oxynitride fibers,” Chemistry of Materials, vol. 22, no. 13, pp. 4045–4055, 2010.
View at: Publisher Site | Google Scholar
S. M. Gupta and M. Tripathi, “A review of TiO₂ nanoparticles,” Chinese Science Bulletin, vol. 56, pp. 1639–1657, 2011.
View at: Publisher Site | Google Scholar
N. Tomić, M. Grujić-Brojčin, N. Finčur et al., “Photocatalytic degradation of alprazolam in water suspension of brookite type TiO₂ nanopowders prepared using hydrothermal route,” Materials Chemistry and Physics, vol. 163, pp. 518–528, 2015.
View at: Publisher Site | Google Scholar
H. Cheng and A. Selloni, “Surface and subsurface oxygen vacancies in anatase TiO₂ and differences with rutile,” Physical Review B, vol. 79, no. 9, Article ID 092101, 2009.
View at: Publisher Site | Google Scholar
L. Kernazhitsky, V. Shymanovska, V. Naumov et al., “Room temperature photoluminescence of mixed titanium–manganese oxides,” Journal of Luminescence, vol. 187, pp. 521–527, 2017.
View at: Publisher Site | Google Scholar
J. Shi and X. Wang, “Growth of rutile titanium dioxide nanowires by pulsed chemical vapor deposition,” Crystal Growth & Design, vol. 11, no. 4, pp. 949–954, 2011.
View at: Publisher Site | Google Scholar
M. Aqeel, M. Ikram, M. Imran et al., “TiO₂ Co-doped with Zr and Ag shows highly efficient visible light photocatalytic behaviour suitable for treatment of polluted water,” RCS Advances, vol. 10, no. 69, pp. 42235–42248, 2020.
View at: Publisher Site | Google Scholar
M. Ikram, J. Hassan, A. Raza et al., “Photocatalytic and bactericidal properties and molecular docking analysis of TiO₂ nanoparticles conjugated with Zr for environmental remediation,” RCS Advances, vol. 10, no. 50, pp. 30007–30024, 2020.
View at: Publisher Site | Google Scholar
K. A. Malinger, A. Maguer, A. Thorel, A. Gaunand, and J.-F. Hochepied, “Crystallization of anatase nanoparticles from amorphous precipitate by a continuous hydrothermal process,” Chemical Engineering Journal, vol. 174, no. 1, pp. 445–451, 2011.
View at: Publisher Site | Google Scholar
K. Namratha and K. Byrappa, “Novel solution routes of synthesis of metal oxide and hybrid metal oxide nanocrystals,” Progress in Crystal Growth and Characterization of Materials, vol. 58, no. 1, pp. 14–42, 2012.
View at: Publisher Site | Google Scholar
B. K. Mutuma, G. N. Shao, W. D. Kim, and H. T. Kim, “Sol–gel synthesis of mesoporous anatase–brookite and anatase–brookite–rutile TiO₂ nanoparticles and their photocatalytic properties,” Journal of Colloid and Interface Science, vol. 442, pp. 1–7, 2015.
View at: Publisher Site | Google Scholar
L. Agartan, D. Kapusuz, J. Park, and A. Ozturk, “Effect of initial water content and calcination temperature on photocatalytic properties of TiO₂ nanopowders synthesized by the sol–gel process,” Ceramics International, vol. 41, no. 10, pp. 12788–12797, 2015.
View at: Publisher Site | Google Scholar
R. S. Dubey, “Temperature-dependent phase transformation of TiO₂ nanoparticles synthesized by sol–gel method,” Materials Letters, vol. 215, pp. 312–317, 2018.
View at: Publisher Site | Google Scholar
S. Sugapriya, R. Sriram, and S. Lakshmi, “Effect of annealing on TiO₂ nanoparticles,” Optik, vol. 124, no. 21, pp. 4971–4975, 2013.
View at: Publisher Site | Google Scholar
C. R. Tubío, F. Guitián, J. R. Salgueiro, and A. Gil, “Anatase and rutile TiO₂ monodisperse microspheres by rapid thermal annealing: a method to avoid sintering at high temperatures,” Materials Letters, vol. 141, pp. 203–206, 2015.
View at: Publisher Site | Google Scholar
D. S. Kim, S. J. Han, and S.-Y. Kwak, “Synthesis and photocatalytic activity of mesoporous TiO₂ with the surface area, crystallite size, and pore size,” Journal of Colloid and Interface Science, vol. 316, no. 1, pp. 85–91, 2007.
View at: Publisher Site | Google Scholar
L. Kernazhitsky, V. Shymanovska, T. Gavrilko et al., “Room temperature photoluminescence of anatase and rutile TiO₂ powders,” Journal of Luminescence, vol. 146, pp. 199–204, 2014.
View at: Publisher Site | Google Scholar
L. Yu, X. Yang, J. He, Y. He, and D. Wang, “One-step hydrothermal method to prepare nitrogen and lanthanum co-doped TiO₂ nanocrystals with exposed {001} facets and study on their photocatalytic activities in visible light,” Journal of Alloys and Compounds, vol. 637, pp. 308–314, 2015.
View at: Publisher Site | Google Scholar
L. Kadri, G. Bulai, A. Carlescu et al., “Effect of target sintering temperature on the morphological and optical properties of pulsed laser deposited TiO₂ thin films,” Coatings, vol. 11, no. 5, Article ID 561, 2021.
View at: Publisher Site | Google Scholar
M. K. Hossain, M. F. Pervez, M. N. H. Mia et al., “Annealing temperature effect on structural, morphological and optical parameters of mesoporous TiO₂ film photoanode for dye-sensitized solar cell application,” Materials Science-Poland, vol. 35, no. 4, pp. 868–877, 2017.
View at: Publisher Site | Google Scholar
S. Chao, V. Petrovsky, and F. Dogan, “Effects of sintering temperature on the microstructure and dielectric properties of titanium dioxide ceramics,” Journal of Materials Science, vol. 45, pp. 6685–6693, 2010.
View at: Publisher Site | Google Scholar
M. C. Mathpal, A. K. Tripathi, M. K. Singh, S. P. Gairola, S. N. Pandey, and A. Agarwal, “Effect of annealing temperature on Raman spectra of TiO₂ nanoparticles,” Chemical Physics Letters, vol. 555, pp. 182–186, 2013.
View at: Publisher Site | Google Scholar
H. Dhiflaoui, N. B. Jaber, F. S. Lazar, J. Faure, A. B. C. Larbi, and H. Benhayoune, “Effect of annealing temperature on the structural and mechanical properties of coatings prepared by electrophoretic deposition of TiO₂ nanoparticles,” Thin Solid Films, vol. 638, pp. 201–212, 2017.
View at: Publisher Site | Google Scholar
A. S. Bakri, M. Z. Sahdan, F. Adriyanto et al., “Effect of annealing temperature of titanium dioxide thin films on structural and electrical properties,” AIP Conference Proceedings, vol. 1788, no. 1, Article ID 030030, 2017.
View at: Publisher Site | Google Scholar
H. Bech and A. Leder, “Simultaneous determination of particle size and refractive index by time-resolved Mie scattering,” Optik, vol. 121, no. 20, pp. 1815–1823, 2010.
View at: Publisher Site | Google Scholar
A. Rastar, M. E. Yazdanshenas, A. Rashidi, and S. M. Bidoki, “Estimation and prediction of optical properties of PA6/TiO₂ nanocomposites,” Arabian Journal of Chemistry, vol. 10, Suppl 1, pp. S219–S224, 2017.
View at: Publisher Site | Google Scholar
H. Akherat Doost, M. H. Majles Ara, and E. Koushki, “Synthesis and complete Mie analysis of different sizes of TiO₂ nanoparticles,” Optik, vol. 127, no. 4, pp. 1946–1951, 2016.
View at: Publisher Site | Google Scholar
I. Niskanen, V. Forsberg, D. Zakrisson et al., “Determination of nanoparticle size using Rayleigh approximation and Mie theory,” Chemical Engineering Science, vol. 201, pp. 222–229, 2019.
View at: Publisher Site | Google Scholar
J. R. Dunklin, G. T. Forcherio, and D. Keith Roper, “Gold nanoparticle-polydimethylsiloxane films reflect light internally by optical diffraction and Mie scattering,” Materials Research Express, vol. 2, no. 8, Article ID 085005, 2015.
View at: Publisher Site | Google Scholar
S. D. Delekar, H. M. Yadav, S. N. Achary, S. S. Meena, and S. H. Pawar, “Structural refinement and photocatalytic activity of Fe-doped anatase TiO₂ nanoparticles,” Applied Surface Science, vol. 263, pp. 536–545, 2012.
View at: Publisher Site | Google Scholar
M. Lal, P. Sharma, and C. Ram, “Calcination temperature effect on titanium oxide (TiO₂) nanoparticles synthesis,” Optik, vol. 241, Article ID 166934, 2021.
View at: Publisher Site | Google Scholar
R. Arroyo, G. Córdoba, J. Padilla, and V. H. Lara, “Influence of manganese ions on the anatase–rutile phase transition of TiO₂ prepared by the sol–gel process,” Materials Letters, vol. 54, no. 5-6, pp. 397–402, 2002.
View at: Publisher Site | Google Scholar
W. Zhang and H. Tang, “Rutile nanopowders for pigment production: formation mechanism and particle size prediction,” Chemical Physics Letters, vol. 692, pp. 129–133, 2018.
View at: Publisher Site | Google Scholar
Y. Rambabu, M. Jaiswal, and S. C. Roy, “Effect of annealing temperature on the phase transition, structural stability and photo-electrochemical performance of TiO₂ multi-leg nanotubes,” Catalysis Today, vol. 278, Part 2, pp. 255–261, 2016.
View at: Publisher Site | Google Scholar
V. T. Lukong, K. O. Ukoba, and T. C. Jen, “Heat-assisted sol–gel synthesis of TiO₂ nanoparticles structural, morphological and optical analysis for self-cleaning application,” Journal of King Saud University - Science, vol. 34, no. 1, Article ID 101746, 2022.
View at: Publisher Site | Google Scholar
R. A. Spurr and H. Myers, “Quantitative analysis of anatase-rutile mixtures with an X-ray diffractometer,” Analytical Chemistry, vol. 29, no. 5, pp. 760–762, 1957.
View at: Publisher Site | Google Scholar
A. L. Patterson, “The Scherrer formula for X-ray particle size determination,” Physical Review, vol. 56, no. 10, pp. 978–982, 1939.
View at: Publisher Site | Google Scholar
D. Li, X. Cheng, X. Yu, and Z. Xing, “Preparation and characterization of TiO₂-based nanosheets for photocatalytic degradation of acetylsalicylic acid: influence of calcination temperature,” Chemical Engineering Journal, vol. 279, pp. 994–1003, 2015.
View at: Publisher Site | Google Scholar
N. Rathore, A. Kulshreshtha, R. K. Shukla, and D. Sharma, “Study on morphological, structural and dielectric properties of sol–gel derived TiO₂ nanocrystals annealed at different temperatures,” Physica B: Condensed Matter, vol. 582, Article ID 411969, 2020.
View at: Publisher Site | Google Scholar
S. Saravanan and R. S. Dubey, “Optical and morphological studies of TiO₂ nanoparticles prepared by sol–gel method,” Materials Today: Proceedings, vol. 47, Part 9, pp. 1811–1814, 2021.
View at: Publisher Site | Google Scholar
H. Shi, D. Zeng, J. Li, and W. Wang, “A melting-like process and the local structures during the anatase-to-rutile transition,” Materials Characterization, vol. 146, pp. 237–242, 2018.
View at: Publisher Site | Google Scholar
N. Yuangpho, S. T. T. Le, T. Treerujiraphapong, W. Khanitchaidecha, and A. Nakaruk, “Enhanced photocatalytic performance of TiO₂ particles via effect of anatase–rutile ratio,” Physica E: Low-Dimensional Systems and Nanostructures, vol. 67, pp. 18–22, 2015.
View at: Publisher Site | Google Scholar
Z. He, W. Que, J. Chen, Y. He, and G. Wang, “Surface chemical analysis on the carbon-doped mesoporous TiO₂ photocatalysts after post-thermal treatment: XPS and FTIR characterization,” Journal of Physics and Chemistry of Solids, vol. 74, no. 7, pp. 924–928, 2013.
View at: Publisher Site | Google Scholar
P. Shah, N. Agrawal, N. Reddy Ravuru, and S. Patel, “Ultrafine titanium-dioxide (rutile) based nano-crystalline dispersions as a pigment for waterborne coatings,” Progress in Color, Colorants and Coatings, vol. 15, no. 4, pp. 305–318, 2022.
View at: Publisher Site | Google Scholar
P. Praveen, G. Viruthagiri, S. Mugundan, and N. Shanmugam, “Structural, optical and morphological analyses of pristine titaniu di-oxide nanoparticles–synthesized via sol–gel route,” Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 117, pp. 622–629, 2014.
View at: Publisher Site | Google Scholar
M. S. Ghamsari, M. R. Gaeeni, W. Han, and H.-H. Park, “Highly stable colloidal TiO₂ nanocrystals with strong violet–blue emission,” Journal of Luminescence, vol. 178, pp. 89–93, 2016.
View at: Publisher Site | Google Scholar
N. C. Horti, M. D. Kamatagi, N. R. Patil, S. K. Nataraj, M. S. Sannaikar, and S. R. Inamdar, “Synthesis and photoluminescence properties of titanium oxide (TiO₂) nanoparticles: effect of calcination temperature,” Optik, vol. 194, Article ID 163070, 2019.
View at: Publisher Site | Google Scholar
Y. F. You, C. H. Xu, S. S. Xu et al., “Structural characterization and optical property of TiO₂ powders prepared by the sol–gel method,” Ceramics International, vol. 40, no. 6, pp. 8659–8666, 2014.
View at: Publisher Site | Google Scholar
M. K. Singh and M. S. Mehata, “Temperature-dependent photoluminescence and decay times of different phases of grown TiO₂ nanoparticles: carrier dynamics and trap states,” Ceramics International, vol. 47, no. 23, pp. 32534–32544, 2021.
View at: Publisher Site | Google Scholar
E. L. Simmons, “Diffuse reflectance spectroscopy: a comparison of the theories,” Applied Optics, vol. 14, no. 6, pp. 1380–1386, 1975.
View at: Publisher Site | Google Scholar
M. Sreemany and S. Sen, “A simple spectrophotometric method for determination of the optical constants and band gap energy of multiple layer TiO₂ thin films,” Materials Chemistry and Physics, vol. 83, no. 1, pp. 169–177, 2004.
View at: Publisher Site | Google Scholar
Z. Noorimotlagh, I. Kazeminezhad, N. Jaafarzadeh, M. Ahmadi, Z. Ramezani, and S. Silva Martinez, “The visible-light photodegradation of nonylphenol in the presence of carbon-doped TiO₂ with rutile/anatase ratio coated on GAC: effect of parameters and degradation mechanism,” Journal of Hazardous Materials, vol. 350, pp. 108–120, 2018.
View at: Publisher Site | Google Scholar
A. M. Selman, Z. Hassan, and M. Husham, “Structural and photoluminescence studies of rutile TiO₂ nanorods prepared by chemical bath deposition method on Si substrates at different pH values,” Measurement, vol. 56, pp. 155–162, 2014.
View at: Publisher Site | Google Scholar
S. A. Ahmed, “Annealing effects on structure and magnetic properties of Mn-doped TiO₂,” Journal of Magnetism and Magnetic Materials, vol. 402, pp. 178–183, 2016.
View at: Publisher Site | Google Scholar
K. P. Ghoderao, S. N. Jamble, and R. B. Kal, “Influence of reaction temperature on hydrothermally grown TiO₂ nanorods and their performance in dye-sensitized solar cells,” Superlattices Microstructures, vol. 124, pp. 121–130, 2018.
View at: Publisher Site | Google Scholar
M. Tsega and F. B. Dejene, “Morphological, thermal and optical properties of TiO₂ nanoparticles: the effect of titania precursor,” Materials Research Express, vol. 6, no. 6, Article ID 065041, 2019.
View at: Publisher Site | Google Scholar
W. J. Wiscombe, “Improved Mie scattering algorithms,” Applied Optics, vol. 19, no. 9, pp. 1505–1509, 1980.
View at: Publisher Site | Google Scholar
J. Tan, Y. Xie, F. Wang, L. Jing, and L. Ma, “Investigation of optical properties and radiative transfer of TiO₂ nanofluids with the consideration of scattering effects,” International Journal of Heat and Mass Transfer, vol. 115, pp. 1103–1112, 2017.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2023 Moges Tsega Yihunie. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

658

Downloads

371

Citations

Journal of Nanomaterials

Effect of Temperature Sintering on Grain Growth and Optical Properties of TiO2 Nanoparticles

Abstract

1. Introduction

2. Experimental Methods

3. Results and Discussion

4. Conclusion

Data Availability

Additional Points

Conflicts of Interest

Funding

References

Copyright

Effect of Temperature Sintering on Grain Growth and Optical Properties of TiO₂ Nanoparticles