Effects of thermal oxidation and deposition time on the SERS activity of TiO2 nanostructure films

Jutaporn  WANNAPHUM; Watcharaporn  THONGJOON; Chantana  AIEMPANAKIT; Raumporn  THONGRUANG; Montri  AIEMPANAKIT; Kamon Aiempanakit

doi:10.55713/jmmm.v37i1.2702

Authors

Jutaporn WANNAPHUM Department of Physics, Faculty of Science and Technology, Thammasat University, Pathum Thani, 12121, Thailand
Watcharaporn THONGJOON Department of Physics, Faculty of Science and Technology, Thammasat University, Pathum Thani, 12121, Thailand
Chantana AIEMPANAKIT Division of Physics, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani, 12110, Thailand
Raumporn THONGRUANG Department of Physics, Faculty of Science and Technology, Thammasat University, Pathum Thani, 12121, Thailand
Montri AIEMPANAKIT Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom, 73000, Thailand
Kamon Aiempanakit Department of Physics, Faculty of Science and Technology, Thammasat University, Pathumthani, 12121, Thailand

DOI:

https://doi.org/10.55713/jmmm.v37i1.2702

Keywords:

TiO2 films, DC magnetron sputtering, Thermal oxidation, SERS, OAD

Abstract

Titanium (Ti) nanostructure films were fabricated on glass substrates by DC magnetron sputtering using the oblique angle deposition (OAD) technique with varying deposition times. The as-deposited Ti films were subsequently oxidized in air at 400°C and 500°C to obtain TiO₂ nanostructure films. The effects of deposition time and oxidation temperature on the structural, morphological, and optical properties were systematically investigated and correlated with surface-enhanced Raman scattering (SERS) performance toward methylene blue (MB) molecules. Increasing both deposition time and oxidation temperature led to thicker films, larger grains, and enhanced crystallinity with higher surface roughness. The optical band gap gradually decreased as deposition time increased, a trend associated with microstructural evolution and improved crystallinity during thermal oxidation. Among all samples, the TiO₂ film oxidized at 400°C with a deposition time of 4 min exhibited the highest Raman enhancement, with a maximum enhancement factor (EF) of approximately 4.00 ± 0.064 (mean ± SD, n = 5), indicating that moderate oxidation promotes optimal nanostructured surface and charge-transfer efficiency. These findings highlight the important role of deposition time and oxidation conditions in governing the SERS activity of TiO₂ nanostructure films.

Downloads

Download data is not yet available.

References

L. Yang, X. Jiang, W. Ruan, B. Zhao, W. Xu, and J. R. Lombardi, "Charge-transfer induced surface-enhanced Raman scattering on Ag–TiO2 nanoparticles," Journal of Physical Chemistry C, vol. 113, no. 39, pp. 16226–16231, 2009. DOI: https://doi.org/10.1021/jp903600r

T. Rajh, N. M. Dimitrijevic, M. Bissonnette, T. Koritarov, and V. Konda, "SERS of nanoparticles (TiO2 hybrid composites)," Journal of the American Chemical Society, vol. 131, no. 32, pp. 12090‒12091, 2009.

Z. Zhao, and H. Xu, "Charge-transfer process in surface-enhanced Raman scattering on semiconductor nanomaterials," Nanomaterials, vol. 11, no. 8, p. 2110, 2021.

S. Yang, J. Yao, Y. Quan, M. Hu, R. Su, M. Gao, D. Han, and J. Yang, "Monitoring the charge-transfer process in a Nd-doped ZnO semiconductor SERS substrate," Light: Science and Applications, vol. 9, p. 128, 2020. DOI: https://doi.org/10.1038/s41377-020-00361-0

T. T. Tran, B. D. Nguyen, T. T. Pham, T. C. Doan, H. V. Pham, T. T. Nguyen, and D. D. Nguyen, "Study of charge transfer contribution to surface-enhanced Raman scattering on octahedral Cu2O nanostructures," Vietnam Journal of Chemistry, vol. 60, no. 4, pp. 491–499, 2022. DOI: https://doi.org/10.15625/0868-3166/16787

N. T. Phuc, N. V. Duy, and N. V. Hieu, "Increasing charge transfer of SERS by the combination of two semiconductors in Ag/a-Al2O3-Al/ZnO nanostructures," RSC Advances, vol. 13, no. 18, pp. 10237–10247, 2023.

J. F. Arenas, I. López-Tocón, J. C. Otero, and J. I. Marcos, "Charge-transfer processes in surface-enhanced Raman scattering: Franck–Condon active vibrations of pyrazine," Journal of Physical Chemistry, vol. 100, no. 41, pp. 16410–16416, 1996. DOI: https://doi.org/10.1021/jp953712y

M. A. Apostolaki, M. Farsari, M. Vamvakaki, and A. Ranella, "Interplay of plasmonic and charge transfer effects for SERS in WO3/TiO2 inverse opal films with Ag nanoparticles," Materials Advances, vol. 6, pp. 27–38, 2025. DOI: https://doi.org/10.1039/D4MA00995A

Y. Fang, X. Li, H. Wang, and J. Zhang, "Uniform 3D SERS substrate SiO2, AuAg collaborate with target-mediated DNA network structure as a signal amplifier for ultrasensitive detection of miRNA-21," Sensors and Actuators, B: Chemical, vol. 288, p. 117777, 2025. DOI: https://doi.org/10.1016/j.bios.2025.117777

J. Li, Q. Chen, Y. Xu, X. Zhang, and Y. Wang, "Fabrication and SERS performance of SiO2, Ag core–shell nanoparticle arrays," Journal Nanophotonics, vol. 20, pp. 8131–8144, 2025. DOI: https://doi.org/10.1007/s11468-025-02865-0

M. V. Zamarripa, A. A. Rivera, U. Sierra, P. Salas, A. H. Serafín-Muñoz, and G. Ramírez-García, "Improved charge-transfer resonance in graphene oxide/ZrO2 substrates for plasmonic-free SERS determination of methyl parathion," Chemosphere, vol. 320, p. 137974, 2023. DOI: https://doi.org/10.1016/j.chemosphere.2023.138081

K. Pupel, Ł. Bujak, A. Święch, and A. Kamińska, "Direct SERS detection of folic acid using modified graphene oxide–gold nano-bowl composites," ACS Omega, vol. 9, no. 48, pp. 59351–59364, 2024. DOI: https://doi.org/10.1021/acsomega.4c09696

S. Li, S. Yang, Y. Chen, L. Sun, H. Zhang, and H. Xu, "TiO2 compact layer induced charge transfer enhancement in three-dimensional TiO2-Ag SERS substrates," Journal of Materials Chemistry C, vol. 11, pp. 8270‒8280, 2023.

N. Serginay, E. Yilmaz, A. Yildirim, and M. Ozdemir, "Silver nanostructure-decorated hierarchical titanium dioxide nano-structures for highly sensitive SERS detection," Applied Surface Science, vol. 610, p. 155466, 2023. DOI: https://doi.org/10.1016/j.catcom.2023.106672

H. Zhai, C. Zhu, X. Wang, Y. Yuan and H. Tang, "Arrays of Ag-nanoparticles decorated TiO2 nanotubes as reusable three-dimensional surface-enhanced Raman scattering substrates for molecule detection," Frontiers in Chemistry, vol. 10, p. 992236, 2022. DOI: https://doi.org/10.3389/fchem.2022.992236

M. Pisarek, M. Krawczyk, M. Hołdynski, ́ R. Ambroziak, K. Bienkowski, ́ A. Roguska, J. Krajczewski, and A. Kudelski, " Hybrid nanostructures based on TiO2 nanotubes with Ag, Au, or bimetallic Au−Ag deposits for Surface-Enhanced Raman Scattering (SERS) Applications," Journal of Physical Chemistry C, vol. 127, pp. 24200−24210, 2023. DOI: https://doi.org/10.1021/acs.jpcc.3c04147

W. Yang, Q. Ou, C. Li, M. Cheng, W. Li, and Y. Liu, "Ultra-sensitive flower-like TiO2/Ag substrate for SERS detection of pigments and melamine," RSC Advances, vol. 12, pp. 6958‒6965, 2022. DOI: https://doi.org/10.1039/D1RA08128D

J. Wu, S. Lo, K. Song, B. K. Vijayan, W. Li, K. A. Gray, and V. P. Dravid, “Growth of rutile TiO2 nanostructures on anatase TiO2 thin films on Si-based substrates,” Journal of Materials Research, vol. 26, no. 13, pp. 1646–1652, 2011. DOI: https://doi.org/10.1557/jmr.2011.190

Z. Ding, L. Zhang, W. Xu, J. Li, Y. Wang, and L. Chen, "Ag array SERS substrate for quantitative and multiplex analysis based on TiO2 nanostructure-Ag hybrid structures," RSC Advances, vol. 13, pp. 8270‒8280, 2023. DOI: https://doi.org/10.1039/D3RA00094J

S. A. A. Anaam, and M. Z. Sahdan, "Precursor-concentration-controlled morphology of TiO2 nanorod/nanoflower films for enhanced photoelectrochemical water splitting and investigating their growth mechanism," Bulletin of Chemical Reaction Engineering and Catalysis, vol. 19, pp. 15‒31, 2024. DOI: https://doi.org/10.9767/bcrec.20061

A. Tighineanu, T. Ruff, S. Albu, R. Hahn, and P. Schmuki, "Conductivity of TiO2 nanotubes: Influence of annealing time and temperature," Chemical Physics Letters, vol. 494, pp. 260‒263, 2010. DOI: https://doi.org/10.1016/j.cplett.2010.06.022

L. Noel, A. Khitous, C. Molinaro, H. W. Zan, D. Berling, F. Grasset, and O. Soppera, "Laser direct writing of crystallized TiO2 by photothermal eﬀect induced by gold nanoparticles," Advanced Materials Technologies, vol. 9, p. 2300407, 2024. DOI: https://doi.org/10.1002/admt.202300407

S. Kumar, H. Sharma, J. Yadav, J. Prasad, and M. Singh, "TiO2 thin films fabrication and characterization in response to heat treatment," Oriental Journal of Chemistry, vol. 40, no. 4, pp. 1109‒1115, 2024. DOI: https://doi.org/10.13005/ojc/400424

N. R. Mathews, E. R. Morales, M. A. Cortés-Jacome, and J. A. Toledo Antonio, "TiO2 thin films-influence of annealing temperature on structural, optical and photocatalytic properties," Solar Energy, vol. 83, no. 6, pp. 1499‒1508, 2009. DOI: https://doi.org/10.1016/j.solener.2009.04.008

N. Chaabia, D. Abdi, A. Kamarchou, A. Berchi, F. Rahal, and S. Benhamida, "Preparation of amorphous and crystalline titanium dioxide on FTO: ITS characterization and photo- catalytic effect on eriochrome black T," Journal of Nanomaterials and Biostructures, vol. 16, no. 4, pp. 1235‒1242, 2021. DOI: https://doi.org/10.15251/DJNB.2021.164.1235

C. Aiempanakit, and K. Aiempanakit, "Structural development and phase transformation behavior of thermally-oxidization Ti by sputtering power and OAD technique," Materials Chemistry and Physics, vol. 280, p. 125814, 2022. DOI: https://doi.org/10.1016/j.matchemphys.2022.125814

W. Shi, J. C. Lin, R. Da, R. Li, Z. Li, Z. Feng, L. Lin, R. Zhang, and Z. Wang, “UV-irradiated and SPS-constructed vacancy-rich CO-doped TiO2 for highly sensitive SERS detection via enhanced charge transfer,” ACS Applied Materials and Interfaces, vol. 17, no. 39, pp. 55576–55586, 2025. DOI: https://doi.org/10.1021/acsami.5c12698

S. K. Islam and A. Ponte, “Charge-transfer and SERS coupling on TiO2,” American Journal of Analytical Chemistry, vol. 14, no. 11, pp. 519–530, 2023. DOI: https://doi.org/10.4236/ajac.2023.1411030

J. Saari, H. Ali-Löyty, K. Lahtonen, M. Hannula, L. Palomäki, A. Tukiainen, and M. Valden, “Low-temperature route to direct amorphous to rutile crystallization of TiO2 thin films grown by atomic layer deposition,” The Journal of Physical Chemistry C, vol. 126, no. 36, pp. 15357‒15366, 2022. DOI: https://doi.org/10.1021/acs.jpcc.2c04905

V. T. Lukong, K. Ukoba, K. O. Yoro, and T. C. Jen, "Annealing temperature variation and its influence on the self-cleaning properties of TiO2 thin films," Heliyon, vol. 8, p. e09048, 2022. DOI: https://doi.org/10.1016/j.heliyon.2022.e09460

A. A. Al-Samarai, "Structural and optical properties of annealed TiO2 powder prepared by sol-gel method," Engineering And Technology Journal, vol. 41, no. 12, pp. 1683‒1693, 2023.

A. R. Kamrosni, C. H. Dewi Suryani, A. Azliza, A. B. A. M. Mustafa, M. S. M. A. Anuar, M. Norsuria, V. Chobpattana, L. Kaczmarek, B. Jez, and M. Nabialek, "Microstructural studies of Ag/TiO2 thin film; effect of annealing temperature on surface roughness and crystallite size," Archives of Metallurgy and Materials, vol. 67, no. 1, pp. 241‒245, 2022. DOI: https://doi.org/10.24425/amm.2022.137496

L. He, D. R. T. Zahn, and T. I. Madeira, "Photocatalytic performance of sol-gel prepared TiO2 thin films annealed at different temperatures," Materials, vol. 16, p. 5494, 2023. DOI: https://doi.org/10.3390/ma16155494

S. D. Al-Algawi, R. T. Rasheed, and Z. R. Rhoomi, " Structural and optical properties of annealed TiO2 powder synthesized by hydrothermal method," Iraqi Journal of Science, vol. 58, no. 3C, pp. 1683‒1693, 2017. DOI: https://doi.org/10.24996/ijs.2017.58.3C.12

Y. Alaya, R. Souissi, M. Toumi, M. Madani, L. El Mir, N. Bouguila, and S. Alaya, "Annealing effect on the physical properties of TiO2 thin films deposited by spray pyrolysis," RSC Advances, vol. 13, no. 32, pp. 21852‒21860, 2023. DOI: https://doi.org/10.1039/D3RA02387G

Z. Zhao, M. Zhang, and X. Sun, "Charge-transfer process in surface-enhanced Raman scattering based on energy level locations of rare-earth Nd3+-doped TiO2 nanoparticles," Nano-materials, vol. 11, no. 8, p. 2063, 2021. DOI: https://doi.org/10.3390/nano11082063

L. Yang, X. Jiang, W. Ruan, B. Zhao, W. Xu, and J. R. Lombardi, "Observation of enhanced Raman scattering for molecules adsorbed on TiO2 nanoparticles: Charge-transfer contribution," Journal of Physical Chemistry C, vol. 112, no. 50, pp. 20095‒20098, 2008. DOI: https://doi.org/10.1021/jp8074145

Q. Chen, M. Betker, C. Harder, C. J. Brett, M. Schwartzkopf, N. M. Ulrich, M. E. Toimil-Molares, C. Trautmann, L. D. Söderberg, C. L. Weindl, V. Körstgens, P. Müller-Buschbaum, M. Ma, and S. V. Roth, "Biopolymer-templated deposition of ordered and polymorph titanium dioxide thin films for improved surface-enhanced raman scattering sensitivity," Advanced Functional Materials, vol. 32, no. 8, p. 2108556, 2022. DOI: https://doi.org/10.1002/adfm.202108556

W. Kaewwiset, W. Onreabroy, and P. Limsuwan, "Effect of annealed temperatures on the morphology of TiO2 films," Kasetsart Journal (Natural Science), vol. 42, pp. 341‒345, 2008.

S. Prucnal, R. Gago, D. G. Calatayud, L. Rebohle, M. O. Liedke, M. Butterling, A. Wagner, M. Helm, and S. Zhou, "TiO2 phase engineering by millisecond range annealing for highly efficient photocatalysis," Journal of Physical Chemistry C, vol. 127, no. 26, pp. 12686‒12694, 2023. DOI: https://doi.org/10.1021/acs.jpcc.3c01165

M. Rogala, G. Bihlmayer, P. Dabrowski, C. Rodenbücher, D. Wrana, F. Krok, Z. Klusek, and K. Szot , "Self-reduction of the native TiO2 (110) surface during cooling after thermal annealing – in- operando investigations," Scientific Reports, vol. 9, no. 1, p. 12539, 2019. DOI: https://doi.org/10.1038/s41598-019-48837-3

H.-Y. Wu, H.-C. Lin, Y.-H. Liu, K.-L. Chen, Y.-H. Wang, Y.-S. Sun, and J.-C. Hsu, "Highly sensitive, robust, and recyclable TiO2/AgNP substrate for SERS detection," Molecules, vol. 27, no. 19, p. 6755, 2022. DOI: https://doi.org/10.3390/molecules27196755

I. Sta, M. Jlassi, M. Hajji, M. F. Boujmil, R. Jerbi, and M. Kandyla, "Structural and optical properties of TiO2 thin films prepared by spin coating," Journal of Sol-Gel Science and Technology, vol. 59, pp. 476‒481, 2011.

H. S. Ali, A. A. Al-Hassan, S. H. Al-Harthi, E. A. Al-Abbad, and A. Shaima, "Influence of thickness on the physical properties of nanostructured TiO2 thin films," Chalcogenide Letters, vol. 17, no. 1, pp. 23‒31, 2020.

H. T. Nguyen, T. T. Le, V. T. Nguyen, T. T. Le, and N. T. Tran, "Annealing time effect on the structural, optical, and electrical properties of TiO2 thin films prepared by spin coating," Letters in Applied NanoBioScience, vol. 134, p. 169, 2024. DOI: https://doi.org/10.33263/LIANBS134.169

A. A. Hussein, A. S. Hassanien, and O. H. Abd-Elkader, "Effects of annealing temperature on structural, morphological, optical properties and photocatalytic activity of TiO2 thin films," Journal of Engineering and Applied Science, vol. 11, pp. 4047‒4053, 2016.

Z. Wang, Y. Hu, Y. Zhang, L. Yang, Y. Gu, and S. Wang, "Effect of microstructure of TiO2 thin films on optical band gap energy," Chinese Physics Letters, vol. 22, no. 7, pp. 1727‒1729, 2005.

Z. M. Rosli, and N. D. Johari, “Band gap energy and photo-catalytic efficiency of TiO2 thin films deposited via dip and spin coating under visible light,” Journal of Power and Energy Engineering, vol. 13, no. 12, pp. 1‒13, 2025. DOI: https://doi.org/10.4236/jpee.2025.1312001

M. H. Mithun, A. Sayed, and I. Rahaman, “The effect of band-gap on TiO2 thin film considering various parameters,” Proceedings of Engineering and Technology Innovation, vol. 19, pp. 45‒52, 2021. DOI: https://doi.org/10.46604/peti.2021.7712

Y. Li, Y. Wang, Y. Zhang, Y. Liu, and L. Zhang, "The charge transfer effect on SERS in a gold-decorated surface defect anatase nanosheet/methylene blue (MB) system," Journal for new directions in chemistry, vol. 45, no. 45, pp. 20952–20959, 2021. DOI: https://doi.org/10.1039/D1NJ03941E

G. Singh, A. Kumar, R. Kumar, and P. Singh, "Deciphering the role of carbon quantum dots-metal heterojunction in SERS enhancement for methylene blue detection," Journal of Applied Physics, vol. 138, no. 20, p. 203103, 2025.

Y. Zhang, Y. Liu, J. Li, and Z. Wang, "TiO2 thickness-dependent charge transfer in an ordered Ag/TiO2/Ni nanopillar arrays hybrid substrate," Nanomaterials, vol. 12, no. 10, p. 1688, 2022. DOI: https://doi.org/10.3390/ma15103716

S. Adesoye, and K. Dellinger, "ZnO and TiO2 nanostructures for surface-enhanced Raman scattering-based bio-sensing: A review," Sensing and Bio-Sensing Research, vol. 37, p. 100499, 2022. DOI: https://doi.org/10.1016/j.sbsr.2022.100499

S. Li, S. Yang, Y. Chen, L. Sun, H. Zhang, and H. Xu, "TiO2 compact layer induced charge transfer enhancement in three-dimensional TiO2-Ag SERS substrates," Journal of Materials Chemistry C, vol. 11, no. 14, pp. 4972‒4981, 2023.

X. Zhang, J. Li, Y. Liu, and H. Wang, "TiO2 nanofoam-nano-tube array for surface-enhanced Raman spectroscopy," ACS Applied Nano Materials, vol. 1, no. 11, pp. 6115–6122, 2018. DOI: https://doi.org/10.1021/acsanm.8b01566

E. C. Le Ru, and P. G. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy and Related Plasmonic Effects. Amsterdam, The Netherlands: Elsevier, p.185, 2009. DOI: https://doi.org/10.1016/B978-0-444-52779-0.00010-6

S. Schlücker, "Surface-enhanced raman spectroscopy: concepts and chemical applications," Angewandte Chemie International Editionvol. 53, no. 19, pp. 4756‒4795, 2014. DOI: https://doi.org/10.1002/anie.201205748

J. Langer, D. J. de Aberasturi, J. Aizpurua, R. A. Alvarez-Puebla, J. J. Baumberg, S. I. Bozhevolnyi, and L. M. Liz-Marzan, "Present and future of surface-enhanced Raman scattering," ACS Nano, vol. 14, no. 1, pp. 28‒117, 2020.

B. Santara, P. K. Giri, K. Imakita, and M. Fujii, “Evidence for Ti interstitial induced extended visible absorption and near infrared photoluminescence from undoped TiO2 nanoribbons: An in situ photoluminescence study,” Journal of Physical Chemistry C, vol. 117, no. 23, pp. 23402−23411, 2013. DOI: https://doi.org/10.1021/jp408249q

D. K. Pallotti, L. Passoni, P. Maddalena, F. Di Fonzo, and S. Lettieri, “Photoluminescence mechanisms in anatase and rutile TiO2,” Journal of Physical Chemistry C, vol. 121, no. 15, pp. 9011–9021, 2017. DOI: https://doi.org/10.1021/acs.jpcc.7b00321