Enhanced Room-Temperature Gas Sensing Performance of 2% Mn-Doped Sri Lankan Natural Graphite Thin-Film Sensors for Ammonia, Acetone, and Ethanol vapors Detection

Year : 2026 | Volume : 13 | Issue : 02 | Page : 39 49
By

I.G.P.N. Karunasena,

P.G.D.C.K. Karunarathna,

Roshan Thotagamuge,

P. Samarasekara4,

  1. Research Assistant, Postgraduate Institute of Science, University of Peradeniya, Peradeniya, Peradeniya, Sri Lanka
  2. Senior lecturer, Department of Nano Science Technology, Faculty of Technology, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka
  3. Senior lecturer, Department of Optometry, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
  4. Senior Professor, Department of Physics, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka

Abstract

The development of room-temperature gas sensors with high sensitivity, fast response, and low-cost remains a critical challenge for environmental monitoring and safety applications. In this work, we report the fabrication and characterization of a 2% Mn-doped Sri Lankan natural graphite thin-film sensor for the detection of ammonia (NH3), ethanol (C2H5OH), and acetone (C3H6O) vapors under ambient conditions. The sensor was prepared using the doctor-blade coating method on Indium Tin Oxide (ITO) glass substrates, followed by thermal annealing at 100°C. Structural and morphological analyses using X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful incorporation of Mn, with an estimated porosity of 18.94%. Gas sensing measurements revealed that Mn doping significantly enhances the performance of natural graphite. The highest response was observed for C3H6O with a sensitivity of 36.92%, followed by NH3 (9.77%) and C2H5OH (9.55%). Compared to undoped graphite, the Mn-doped sensor exhibits improved sensitivity and reduced response/recovery times, particularly showing a substantial decrease in recovery time due to enhanced adsorption-desorption kinetics. The improved sensing behavior is attributed to Mn-induced surface activation, increased defect sites, and enhanced charge transfer interaction between gas molecules and the graphite surface. The overall results demonstrate that Mn-doped Sri Lankan natural graphite is a promising low-cost material for efficient gas sensing applications. This study provides a viable pathway for developing simple, scalable, and high-performance gas sensors based on doped natural graphite systems.

Keywords: Doctor-blade method, Gas sensitivity, Gas sensors, Mn-doped graphite, Sri Lankan graphite, Ammonia sensing, Thin-film sensor

[This article belongs to Journal of Thin Films, Coating Science Technology & Application ]

How to cite this article: I.G.P.N. Karunasena, P.G.D.C.K. Karunarathna, Roshan Thotagamuge, P. Samarasekara4. Enhanced Room-Temperature Gas Sensing Performance of 2% Mn-Doped Sri Lankan Natural Graphite Thin-Film Sensors for Ammonia, Acetone, and Ethanol vapors Detection. Journal of Thin Films, Coating Science Technology & Application. 2026; 13(02):39-49.
How to cite this URL: I.G.P.N. Karunasena, P.G.D.C.K. Karunarathna, Roshan Thotagamuge, P. Samarasekara4. Enhanced Room-Temperature Gas Sensing Performance of 2% Mn-Doped Sri Lankan Natural Graphite Thin-Film Sensors for Ammonia, Acetone, and Ethanol vapors Detection. Journal of Thin Films, Coating Science Technology & Application. 2026; 13(02):39-49. Available from: https://journals.stmjournals.com/jotcsta/article=2026/view=255478

References

  1. Lin PC, Villarreal R, Achilli S, Bana H, Nair MN, Tejeda A, et al. Doping graphene with substitutional Mn. ACS Nano. 2021;15(3):5449–5458. doi:10.1021/acsnano.1c00139. PMID:33596385.
  2. Grotti M, Leardi R, Gnecco C, Frache R. Determination of manganese by graphite furnace atomic absorption spectrometry: Matrix effect control by multiple linear regression model. Spectrochim Acta B. 1999;54(5):845–851. doi:10.1016/S0584-8547(99)00027-0.
  3. Lei Y, Butler D, Lucking MC, Zhang F, Xia T, Fujisawa K, et al. Single-atom doping of MoS2 with manganese enables ultrasensitive detection of dopamine: Experimental and computational approach. Sci Adv. 2020;6(32). doi:10.1126/sciadv.abc4250. PMID:32821846.
  4. Wang W, Zhang Y, Shen C, Chai Y. Adsorption of CO molecules on doped graphene: A first-principles study. AIP Adv. 2016;6(2). doi:10.1063/1.4942491.
  5. Karunasena IGPN, Rathnayake C, Thotagamuge R, Samarakoon SPAUK, Samarasekara P. Synthesis and characterization of thin film gas sensors using Sri Lankan natural graphite: comparative analysis of sensitivity to ammonia, acetone, and ethanol vapors. Ionic Res Eng J. 2026;9(7):2244-52. doi:10.64388/IREV9I7-1713855.
  6. Mohammadi-Manesh E, Ahmadvand N, Rahmani S. Ag-doped monolayer and bilayer graphene for the gas sensor and purifier of industrial oils. Comput Theor Chem. 2023;1228:114274. doi:10.1016/j.comptc.2023.114274.
  7. Gui Y, Peng X, Liu K, Ding Z. Adsorption of C2H2, CH4 and CO on Mn-doped graphene: Atomic, electronic, and gas-sensing properties. Physica E Low Dimens Syst Nanostruct. 2020;119:113959. doi:10.1016/j.physe.2020.113959.
  8. Song EH, Yan JM, Lian JS, Jiang Q. External electric field catalyzed N2O decomposition on Mn-embedded graphene. J Phys Chem C. 2012;116(38):20342–20348. doi:10.1021/jp304757f.
  9. Xie T, Tian C, Wang P, Zhao G. The adsorption behavior of gas molecules on Mn/N- and Mn-doped graphene. Nanomaterials (Basel). 2024;14(16):1353. doi:10.3390/nano14161353. PMID:39195391.
  10. Yi M, Shen Z, Zhang X, Ma S. Achieving concentrated graphene dispersions in water/acetone mixtures by the strategy of tailoring Hansen solubility parameters. J Phys D Appl Phys. 2013;46(2):025301. doi:10.1088/0022-3727/46/2/025301.
  11. Jiang Z, Huang K, Yang D, Wang S, Zhong H, Jiang C. Facile preparation of Mn3O4 hollow microspheres via reduction of pentachloropyridine and their performance in lithium-ion batteries. RSC Adv. 2017;7(14):8264–8271. doi:10.1039/C6RA24803A.
  12. Salvatore M, Carotenuto G, De Nicola S, Camerlingo C, Ambrogi V, Carfagna C. Synthesis and characterization of highly intercalated graphite bisulfate. Nanoscale Res Lett. 2017;12(1):167. doi:10.1186/s11671-017-1930-2. PMID:28274088.
  13. Dahamni MA, Ghamnia M, Naceri SE, Fauquet C, Tonneau D, Pireaux JJ, et al. Spray pyrolysis synthesis of pure and Mg-doped manganese oxide thin films. Coatings. 2021;11(5):598. doi:10.3390/coatings11050598.
  14. Barnakov CN, Khokhlova GP, Popova AN, Sozinov SA, Ismagilov ZR. XRD characterization of the structure of graphites and carbon materials obtained by the low-temperature graphitization of coal tar pitch. Eurasian Chem Technol J. 2015;17(2):87–93. doi:10.18321/ectj198.
  15. Popova AN. Crystallographic analysis of graphite by X-ray diffraction. Coke Chem. 2017;60(9):361–365. doi:10.3103/S1068364X17090058.
  16. Hassanzadeh-Tabrizi SA. Precise calculation of crystallite size of nanomaterials: A review. J Alloys Compd. 2023;968:171914. doi:10.1016/j.jallcom.2023.171914.
  17. Chakraborthy A, Nuthalapati S, Nag A, Afsarimanesh N, Alahi MEE, Altinsoy ME. A critical review of the use of graphene-based gas sensors. Chemosensors. 2022;10(9):355. doi:10.3390/chemosensors10090355.
Regular Issue Subscription Original Research
Volume 13
Issue 02
Received 18/05/2026
Accepted 27/05/2026
Published 17/06/2026
Publication Time 30 Days

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