Journal of Advanced Materials and Technologies

Journal of Advanced Materials and Technologies

Microstructure, morphology, and electrocatalytic performance of n-type semiconductor DLC coating deposited on Titanium via PECVD

Document Type : Original Reaearch Article

Authors
Alireza Sarshar Noshahr 1
Kourosh Jafarzadeh 2
1 PhD student at Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran.
2 Associate Professor at Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran.
10.30501/jamt.2026.562840.1348
Abstract
Unlocking the full electrochemical potential of diamond-like carbon (DLC) thin films hinges on a nuanced understanding of their synthesis parameters. This study meticulously investigates the profound influence of the methane-to-hydrogen gas ratio on the electrocatalytic performance of DLC films precisely fabricated via direct current plasma-enhanced chemical vapor deposition (DCPECVD). A systematic exploration across methane flow rates from 0.5 to 4.5 sccm revealed a dramatic impact on the film’s microstructure, particularly its sp³/sp² hybridization ratio and grain morphology. The morphology and structure of the samples were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while electrochemical behavior was quantitatively assessed via electrochemical impedance spectroscopy (EIS) and Mott–Schottky analysis. The findings unequivocally establish a direct correlation between methane concentration and both the structural attributes and electrochemical efficacy of the DLC coatings. Strikingly, an optimized methane concentration of 0.5 sccm yielded DLC films with an excellent microstructure, marked by a higher sp³/sp² ratio and finely uniform grain structures, which in turn facilitated markedly enhanced electrocatalytic activity. Furthermore, consistent n-type semiconductor conductivity was observed across all investigated DLC samples.
Keywords
DLC
PECVD
Microstructure
Morphology
Electrocatalytic Performance
Subjects
1.      Baluchova, S., Taylor, A., Mortet, V., Sedlakova, S., Klimša, L., Kopeček, J., Hák, O., & Schwarzová-Pecková, K. (2019). Porous boron doped diamond for dopamine sensing: Effect of boron doping level on morphology and electrochemical  performance. Electrochimica Acta, 327, 135025. https://doi.org/10.1016/j.electacta.2019.135025
2.      Capote, G., Ramírez, M. A., Da Silva, P. C. S., Lugo, D. C., & Trava-Airoldi, V. J. (2016). Improvement of the properties and the adherence of DLC coatings deposited using a modified pulsed-DC PECVD technique and an additional cathode. Surface and Coatings Technology, 308, 70–79. https://doi.org/10.1016/j.surfcoat.2016.08.096
3.      Cataldo, F. (2001). Raman scattering investigation of carbynoid and diamond-like carbon. Fullerene Science and Technology, 9(2), 153–160. https://doi.org/10.1081/FST-100102962
4.      Dennison, J. R., Holtz, M., & Swain, G. (1996). Raman spectroscopy of carbon materials. Spectroscopy, 11(8). https://digitalcommons.usu.edu/mp_facpub/26
5.      Dezfuli, S. M. (2022). Investigating of Structural Evolution of Diamond-Like Carbon Thin Film Applied by Ion Beam Deposition Technology under the Effect of Substrate Temperature. Journal of Advanced Materials and Technologies, Vol. 11, N, 31–42. [ In Persian]. https://doi.org/10.30501/jamt.2022.349543.1233
6.      E. Mohagheghpour et al. (2021). Effect of Silver Clusters Deposition on Wettability and Optical Properties of Diamond like Carbon Films. International Journal of Engineering, Vol. 34,(No. 03,), 706–713. [ In Persian]. https://doi.org/10.5829/ije.2021.34.03c.15
7.      Feng, Y., Lv, J., Liu, J., Gao, N., Peng, H., & Chen, Y. (2011). Influence of boron concentration on growth characteristic and electro-catalytic performance of boron-doped diamond electrodes prepared by direct current plasma chemical vapor deposition. Applied Surface Science, 257(8), 3433–3439.                             https://doi.org/10.1016/j.apsusc.2010.11.041
8.      Ferrari, A. C., & Robertson, J. (2000). Interpretation of Raman spectra of disordered and amorphous carbon. Physical Review B, 61(20), 14095. https://doi.org/10.1103/PhysRevB.61.14095
9.      Ferreira, N. G., Silva, L. L. G., Corat, E. J., & Trava-Airoldi, V. J. (2002). Kinetics study of diamond electrodes at different levels of boron doping as quasi-reversible systems. Diamond and Related Materials, 11(8), 1523–1531. https://doi.org/10.1016/S0925-9635(02)00060-2
10.    Gelderman, K., Lee, L., & Donne, S. W. (2007). Flat-band potential of a semiconductor: using the Mott–Schottky equation. Journal of Chemical Education, 84(4), 685. https://doi.org/10.1021/ed084p685
11.    Guinea, E., Centellas, F., Brillas, E., Cañizares, P., Sáez, C., & Rodrigo, M. A. (2009). Electrocatalytic properties of diamond in the oxidation of a persistant pollutant. Applied Catalysis B: Environmental, 89(3–4), 645–650. https://doi.org/10.1016/j.apcatb.2009.01.028
12.    Han, B., Yan, M., Ju, D., Chai, M., & Sato, S. (2021). Chemical composition and corrosion behavior of aC: H/DLC film-coated titanium substrate in simulated PEMFC environment. Coatings, 11(7), 820. https://doi.org/10.3390/coatings1107082
13.    Hirschorn, B., Orazem, M. E., Tribollet, B., Vivier, V., Frateur, I., & Musiani, M. (2010). Determination of effective capacitance and film thickness from constant-phase-element parameters. Electrochimica Acta, 55(21), 6218–6227. https://doi.org/10.1016/j.electacta.2009.10.065
14.    Hsu, C. H., & Mansfeld, F. (n.d.). Technical Note: Concerning the Conversion of the Constant Phase Element Parameter Y0 into a Capacitance| Corrosion| OnePetro,(nd). https://doi.org/10.5006/1.3280607
15.    Itaya, K., Uchida, I., Toshima, S., & De La Rue, R. M. (1984). Photoelectrochemical Studies of Prussian Blue on n‐Type Semiconductor (n‐TiO2). Journal of the Electrochemical Society, 131(9), 2086. DOI 10.1149/1.2116024
16.    Jana, D., Sun, C.-L., Chen, L.-C., & Chen, K.-H. (2013). Effect of chemical doping of boron and nitrogen on the electronic, optical, and electrochemical properties of carbon nanotubes. Progress in Materials Science, 58(5), 565–635. https://doi.org/10.1016/j.pmatsci.2013.01.003
17.    Jarman, R. H., Ray, G. J., Standley, R. W., & Zajac, G. W. (1986). Determination of bonding in amorphous carbon films: A quantitative comparison of core‐electron energy‐loss spectroscopy and 13C nuclear magnetic resonance spectroscopy. Applied Physics Letters, 49(17), 1065–1067. https://doi.org/10.1063/1.97476
18.    Jo, Y. J., Zhang, T. F., Son, M. J., & Kim, K. H. (2018). Synthesis and electrochemical properties of Ti-doped DLC films by a hybrid PVD/PECVD process. Applied Surface Science, 433, 1184–1191. https://doi.org/10.1016/j.apsusc.2017.10.151
19.    Lugo, D. C., Silva, P. C., Ramirez, M. A., Pillaca, E., Rodrigues, C. L., Fukumasu, N. K., Corat, E. J., Tabacniks, M. H., & Trava-Airoldi, V. J. (2017). Characterization and tribologic study in high vacuum of hydrogenated DLC films deposited using pulsed DC PECVD system for space applications. Surface and Coatings Technology, 332, 135–141. https://doi.org/10.1016/j.surfcoat.2017.07.084
20.    Mansano, R. D., Massi, M., Zambom, L. da S., Verdonck, P., Nogueira, P. M., Maciel, H. S., & Otani, C. (2000). Effects of the methane content on the characteristics of diamond-like carbon films produced by sputtering. Thin Solid Films, 373(1–2), 243–246. https://doi.org/10.1016/S0040-6090(00)01088-9
21.    McLaughlin, M. H. S., Pakpour-Tabrizi, A. C., & Jackman, R. B. (2021). A detailed EIS study of boron doped diamond electrodes decorated with gold nanoparticles for high sensitivity mercury detection. Scientific Reports, 11(1), 9505. https://doi.org/10.1038/s41598-021-89045-2
22.    Mirseyed, S. F., Jafarzadeh, K., Rostamian, A., Semnani, A., Abbasi, H. M., & Ostadhassan, M. (2022). A novel approach to the role of iridium and titanium oxide in deactivation mechanisms of a Ti/(36 RuO2-x IrO2-(64-x) TiO2) coating in sodium chloride solution. Corrosion Science, 206, 110481. https://doi.org/10.1016/j.corsci.2022.110481
23.    Miyai, S., Kobayashi, T., & Terai, T. (2009). Mechanical, thermal, and tribological properties of amorphous carbon films. Japanese Journal of Applied Physics, 48(5S2), 05EC05. DOI 10.1143/JJAP.48.05EC05
24.    Nankya, R., Lee, J., Opar, D. O., & Jung, H. (2019). Electrochemical behavior of boron-doped mesoporous graphene depending on its boron configuration. Applied Surface Science, 489, 552–559. https://doi.org/10.1016/j.apsusc.2019.06.015
25.    Naragino, H., Yoshinaga, K., Tatsuta, S., & Honda, K. (2012). Improvement of conductivity by incorporation of boron atoms in hydrogenated amorphous carbon films fabricated by plasma CVD methods and its electrochemical properties. ECS Transactions, 41(20), 59. DOI 10.1149/1.3687438
26.    Noori, A., & Eshraghi, M. J. (2023). Improvement in Austenitic Stainless Steel Implant via Dual-Layer Coating of TaN-DLC Using Sputtering and PACVD Methods. Advanced Ceramics Progress, 9(3), 31–37. https://doi.org/10.30501/acp.2023.396200.1125
27.    Park, C.-S., Choi, S. G., Jang, J.-N., Hong, M., Kwon, K.-H., & Park, H.-H. (2013). Effect of boron and silicon doping on the surface and electrical properties of diamond like carbon films by magnetron sputtering technique. Surface and Coatings Technology, 231, 131–134. https://doi.org/10.1016/j.surfcoat.2012.01.014
28.    Pillaca, E. J. de D. M., Rebeca, F. B. de O., Martins, G. V., Ferreira, S. R., da Silva, T. F., Rodrigues, C. L., & Trava-Airoldi, V. J. (2024). Preparation of boron-doped diamond-like carbon films via enhanced-PECVD using an additional cathode. Surface and Coatings Technology, 478, 130432. https://doi.org/10.1016/j.surfcoat.2024.130432
29.    Pleskov, Y. V, Krotova, M. D., Elkin, V. V, Ralchenko, V. G., Saveliev, A. V, Pimenov, S. M., & Lim, P.-Y. (2007). n-Type nitrogenated nanocrystalline diamond thin-film electrodes: The effect of the nitrogenation on electrochemical properties. Electrochimica Acta, 52(17), 5470–5478. https://doi.org/10.1016/j.electacta.2007.03.006
30.    Qi, M., Xiao, J., Cheng, Y., Wang, Z., Jiang, A., Guo, Y., & Tao, Z. (2017). Effect of various nitrogen flow ratios on the optical properties of (Hf: N)-DLC films prepared by reactive magnetron sputtering. Aip Advances, 7(8). https://doi.org/10.1063/1.4993631
31.    Robertson, J. (1991). Hard amorphous (diamond-like) carbons. Progress in Solid State Chemistry, 21(4), 199–333. https://doi.org/10.1016/0079-6786(91)90002-H
32.    Robertson, J. (2002). Diamond-like amorphous carbon. Materials Science and Engineering: R:Reports, 37(4–6), 129–281. https://doi.org/10.1016/S0927796X(02)00005-0
33.    Williamson, J., & Isgor, O. B. (2016). Investigation of Mott–Schottky analysis test parameters to study the semiconductive properties of passive films of carbon steel in highly alkaline environments. Advances in Civil Engineering Materials, 5(1), 80–106. https://doi.org/10.1520/ACEM20150031
34.    Wu, J.-B., Lin, M.-L., Cong, X., Liu, H.-N., & Tan, P.-H. (2018). Raman spectroscopy of graphene-based materials and its applications in related devices. Chemical Society Reviews, 47(5), 1822–1873. https://doi.org/10.1039/C6CS00915H
35.    Yamamoto, K., Ichikawa, Y., Nakayama, T., & Tawada, Y. (1988). Relationship between plasma parameters and carbon atom coordination in aC: H Films prepared by RF glow discharge decomposition. Japanese Journal of Applied Physics, 27(8R), 1415. 10.1143/JJAP.27.1415
36.    Yousefi, V., Mohebbi-Kalhori, D., & Samimi, A. (2019). Equivalent electrical circuit modeling of ceramic-based microbial fuel cells using the electrochemical impedance spectroscopy (EIS) analysis. Journal of Renewable Energy and Environment, 6(1), 21–28. https://doi.org/10.30501/jree.2019.95555
Zeng, A., Neto, V. F., Gracio, J. J., & Fan, Q. H. (2014). Diamond-like carbon (DLC) films as electrochemical electrodes. Diamond and Related Materials, 43, 12–22. https://doi.org/10.1016/j.diamond.2014.01.003
Journal of Advanced Materials and Technologies
Volume 14, Issue 4
Winter 2026
Pages 90-104

  • Receive Date 16 December 2025
  • Revise Date 09 February 2026
  • Accept Date 16 June 2026