Downloads

Danushika, G., Yap, P. L., & Losic, D. Oxygen Functional Groups in Graphene Oxide Using Titration Methods: Quantitative Analysis and New Quality Parameters. Graphene Innovation and Technology. 2025. doi: Retrieved from https://ojs.sciltp.com/journals/git/article/view/980
Volume 1, Issue 1, 2025
Copyright (c) 2025 by the authors.
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Article

Oxygen Functional Groups in Graphene Oxide Using Titration Methods: Quantitative Analysis and New Quality Parameters

Gimhani Danushika, Pei Lay Yap, and Dusan Losic *

School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia

* Correspondence: dusan.losic@adelaide.edu.au

Received: 29 November 2024; Revised: 20 January 2025; Accepted: 27 February 2025; Published: 26 March 2025

Abstract: Graphene oxide (GO), an oxidized form of graphene containing various oxygen functional groups, is recognized for its exceptional properties and one of the most valuable graphene-related 2D materials (GR2Ms). Large-scale industrial production of GO materials from graphite involves various chemical oxidation methods, leading to significant variability in their properties, structures, types and composition of oxygen functional groups, which are critical for their practical applications. The quantification of oxygen functional groups in industrially manufactured GO remains largely unexplored and undisclosed in technical data sheets, creating challenges for end-users. Conventional characterization techniques for graphene materials, including SEM, EDAX and XPS, are limited by their spot-characterization nature and inability to reliably assess the bulk chemical properties of GO materials. To address these challenges, in this paper, we present a demonstration of a simple and industrially affordable analytical method using potentiometric titration to quantify the concentration of oxygen functional groups in GO powders and pastes on a bulk scale. Specifically, Boehm and acid-catalysed titrations were combined and successfully employed to determine the concentrations (mmol/g and mass %) of carboxylic, lactone, hydroxyl, carbonyl, epoxy groups and the total oxygen groups. This method has been validated by quantifying oxygen functional groups in industrially GO samples from three different manufacturers. The results revealed substantial differences in the concentrations of oxygen functional groups and total oxygen level of these GO samples, with carboxylic acid groups ranging from 0.89 ± 0.01 to 1.91 ± 0.08 mmol/g, lactone groups from 0.20 ± 0.01 to 1.76 ± 0.26 mmol/g, phenolic groups from 1.12 ± 0.15 to 2.73 ± 0.05 mmol/g, carbonyl groups from 0.65 ± 0.19 to 2.21 ± 0.26 mmol/g, and epoxy groups from 1.15 ± 0.05 to 1.37 ± 0.05 mmol/g. These variations, likely stemming from different GO manufacturing processes, highlight the importance of accurately determining these parameters. Furthermore, based on these measurements, we introduce, for the first time oxygen group indexes (OGI) as a novel quality parameter for distinguishing the quality of industrially produced GO materials. This study demonstrates how these simple, cost-effective methods, when implemented and adopted can significantly contribute to the chemical characterization and quality control of GR2Ms, addressing a critical gap in the graphene industry.

Keywords:

graphene oxide functional groups Boehm titration characterization

References

  1. Ashok Kumar, S.S.; Bashir, S.; Ramesh, K.; Ramesh, S. A review on graphene and its derivatives as the forerunner of the two-dimensional material family for the future. J. Mater. Sci. 2022, 57, 12236–12278. https://doi.org/10.100s7/s10853-022-07346-x.
  2. Chen, D.; Feng, H.; Li, J. Graphene Oxide: Preparation, Functionalization, and Electrochemical Applications. Chem. Rev. 2012, 112, 6027−6053.
  3. Sun, Z.; Kong, P.; Gui, H.; Chen, Z.; Song, Y.; Wang, Y.; Wang, Y.; Kipper, M.J.; Tang, J.; Huang, L. Recent advances in the preparation and application of graphene oxide smart response membranes. Mater. Today Chem. 2024, 41, 102303. https://doi.org/10.1016/j.mtchem.2024.102303.
  4. Ferrari, A.C.; Bonaccorso, F.; Fal’ko, V.; Novoselov, K.S.; Roche, S.; Bøggild, P.; Borini, S.; Koppens, F.H.L.; Palermo, V.; Pugno, N.; et al. Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. Nanoscale 2015, 7, 4598–4810. https://doi.org/10.1039/c4nr01600a.
  5. Otsuka, H.; Urita, K.; Honma, N.; Kimuro, T.; Amako, Y.; Kukobat, R.; Bandosz, T.J.; Ukai, J.; Moriguchi, I.; Kaneko, K. Transient chemical and structural changes in graphene oxide during ripening. Nat. Commun. 2024, 15, 1708. https://doi.org/10.1038/s41467-024-46083-4.
  6. El-Kady, M.F.; Shao, Y.; Kaner, R.B. Graphene for batteries, supercapacitors and beyond. Nat. Rev. Mater. 2016, 1, 16033. https://doi.org/10.1038/natrevmats.2016.33.
  7. Abdolhosseinzadeh, S.; Asgharzadeh, H.; Seop Kim, H. Fast and fully-scalable synthesis of reduced graphene oxide. Sci. Rep. 2015, 5, 10160. https://doi.org/10.1038/srep10160.
  8. Eivazzadeh-Keihan, R.; Alimirzaloo, F.; Aghamirza Moghim Aliabadi, H.; Bahojb Noruzi, E.; Akbarzadeh, A.R.; Maleki, A.; Madanchi, H.; Mahdavi, M. Functionalized graphene oxide nanosheets with folic acid and silk fibroin as a novel nanobiocomposite for biomedical applications. Sci. Rep. 2022, 12, 6205. https://doi.org/10.1038/s41598-022-10212-0.
  9. Kauling, A.P.; Seefeldt, A.T.; Pisoni, D.P.; Pradeep, R.C.; Bentini, R.; Oliveira, R.V.B.; Novoselov, K.S.; Castro Neto, A.H. The Worldwide Graphene Flake Production. Adv. Mater. 2018, 30, 1803784. https://doi.org/10.1002/adma.201803784.
  10. Farivar, F. Unlocking thermogravimetric analysis (TGA) in the fight against “Fake graphene” materials. Carbon 2021, 179, 505–513.
  11. Farjadian, F.; Abbaspour, S.; Sadatlu, M.A.A.; Mirkiani, S.; Ghasemi, A.; Hoseini-Ghahfarokhi, M.; Mozaffari, N.; Karimi, M.; Hamblin, M.R. Recent Developments in Graphene and Graphene Oxide: Properties, Synthesis, and Modifications: A Review. ChemistrySelect 2020, 5, 10200–10219. https://doi.org/10.1002/slct.202002501.
  12. Ikram, R.; Jan, B.M.; Ahmad, W. An overview of industrial scalable production of graphene oxide and analytical approaches for synthesis and characterization. J. Mater. Res. Technol. 2020, 9, 11587–11610.
  13. Mao, S.; Pu, H.; Chen, J. Graphene oxide and its reduction: modeling and experimental progress. RSC Adv. 2012, 2, 2643–2662. https://doi.org/10.1039/C2RA00663D.
  14. Sun, L. Structure and synthesis of graphene oxide. Chin. J. Chem. Eng. 2019, 27, 2251–2260. https://doi.org/10.1016/j.cjche.2019.05.003.
  15. Pendolino, F.; Armata, N. Synthesis, Characterization and Models of Graphene Oxide. In Graphene Oxide in Environmental Remediation Process; Pendolino, F., Armata, N., Eds.; Springer International Publishing: Cham, Switzerland, 2017; pp. 5–21.
  16. Mombeshora, E.T.; Muchuweni, E. Dynamics of reduced graphene oxide: Synthesis and structural models. RSC Adv. 2023, 13, 17633–17655. https://doi.org/10.1039/D3RA02098C.
  17. Khine, Y.Y.; Wen, X.; Jin, X.; Foller, T.; Joshi, R. Functional groups in graphene oxide. Phys. Chem. Chem. Phys. 2022, 24, 26337–26355. https://doi.org/10.1039/D2CP04082D.
  18. Ferrari, I.; Motta, A.; Zanoni, R.; Scaramuzzo, F.A.; Amato, F.; Dalchiele, E.A.; Marrani, A.G. Understanding the nature of graphene oxide functional groups by modulation of the electrochemical reduction: A combined experimental and theoretical approach. Carbon 2023, 203, 29–38. https://doi.org/.
  19. Farivar, F.; Lay Yap, P.; Karunagaran, R.U.; Losic, D. Thermogravimetric Analysis (TGA) of Graphene Materials: Effect of Particle Size of Graphene, Graphene Oxide and Graphite on Thermal Parameters. C 2021, 7, 41.
  20. Dehghanzad, B.; Razavi Aghjeh, M.K.; Rafeie, O.; Tavakoli, A.; Jameie Oskooie, A. Synthesis and characterization of graphene and functionalized graphene via chemical and thermal treatment methods. RSC Adv. 2016, 6, 3578–3585. https://doi.org/10.1039/C5RA19954A.
  21. Losic, D.; Farivar F.; Yap P.L.; Tung T.T.; Nine, J. New insights on energetic properties of graphene oxide (GO) materials and their safety and environmental risks. Sci. Total Environ. 2022, 848, 157743.
  22. Kwan, Y.C.G.; Ng, G.M.; Huan, C.H.A. Identification of functional groups and determination of carboxyl formation temperature in graphene oxide using the XPS O 1s spectrum. Thin Solid Films 2015, 590, 40–48. https://doi.org/10.1016/j.tsf.2015.07.051.
  23. Eng, A.Y.S.; Chua, C.K.; Pumera, M. Refinements to the structure of graphite oxide: absolute quantification of functional groups via selective labelling. Nanoscale 2015, 7, 20256–20266. https://doi.org/10.1039/C5NR05891K.
  24. Boehm, H.-P. Surface chemical characterization of carbons from adsorption studies. In Adsorption by Carbons; Elsevier: Amsterdam, The Netherlands, 2008; pp. 301–327.
  25. Spreadbury, C.; Rodriguez, R.; Mazyck, D. Comparison Between FTIR and Boehm Titration for Activated Carbon Functional Group Quantification. J. Undergrad. Res. 2017, 18, 1–7.
  26. Kim, Y.S.; Park, C. Titration Method for the Identification of Surface Functional Groups; Butterworth-Heinemann: Oxford, UK, 2016; pp. 273–286.
  27. Tararan, A.; Zobelli, A.; Benito, A.M.; Maser, W.K.; Stéphan, O. Revisiting Graphene Oxide Chemistry via Spatially-Resolved Electron Energy Loss Spectroscopy. Chem. Mater. 2016, 28, 3741–3748. https://doi.org/10.1021/acs.chemmater.6b00590.
  28. Ren, H.; Cunha, E.; Sun, Q.; Li, Z.; Kinloch, I.A.; Young, R.J.; Fan, Z. Surface functionality analysis by Boehm titration of graphene nanoplatelets functionalized via a solvent-free cycloaddition reaction. Nanoscale Adv. 2019, 1, 1432–1441. https://doi.org/10.1039/C8NA00280K.
  29. Rabchinskii, M.K.; Ryzhkov, S.A.; Besedina, N.A.; Brzhezinskaya, M.; Malkov, M.N.; Stolyarova, D.Y.; Arutyunyan, A.F.; Struchkov, N.S.; Saveliev, S.D.; Diankin, I.D.; et al. Guiding graphene derivatization for covalent immobilization of aptamers. Carbon 2022, 196, 264–279. https://doi.org/10.1016/j.carbon.2022.04.072.
  30. Tao, W.; Lan, Y.; Zhang, J.; Zhu, L.; Liu, Q.; Yang, Y.; Yang, S.; Tian, G.; Zhang, S. Revealing the Chemical Nature of Functional Groups on Graphene Oxide by Integrating Potentiometric Titration and Ab Initio Calculations. ACS Omega 2023, 8, 24332–24340.
  31. Fidel, R.B.; Laird, D.A.; Thompson, M.L. Evaluation of Modified Boehm Titration Methods for Use with Biochars. J. Environ. Qual. 2013, 42, 1771–1778.
  32. Hernandez-Ortiz, M.; Durán-Muñoz, H.A.; Lozano-Lopes, J.D.; Durón, S.M.; Galván-Valencia, M.; Estevez-Martínez, Y.; Ortiz-Medina, I.; Ramírez-Hernández, L.A.; Cruz-Dominguez, O.; Castaño, V.M. Determination of the Surface Functionality of Nanocarbon Allotropes by Boehm titration. Surf. Rev. Lett. 2020, 27, 1950190.
  33. Pawlicka, A.; Doczekalska, B. Determination of surface oxygen functional groups of active carbons according to the Boehm’s titration method. For. Wood Technol. 2013, 84, 11–14.
  34. Hernández-Ortiz, M.; Lozano-López, J.D.; Durón, S.M.; Galván-Valencia, M.; Estevez-Martínez, Y.; Durán-Muñoz, H.A.; Carrera-Escobedo, J.; Guirette-Barbosa, O.; Ortiz-Medina, I.; Ramírez-Hernández, L.A.; et al. Quantitative Measurement of Functional Groups on Nanocarbon Allotropes Surface by Boehm Titration. J. Micro Nano-Manuf. 2019, 7, 011002.
  35. Hernández Rosas, J.J.; Ramírez Gutiérrez, R.E.; Escobedo-Morales, A.; Chigo Anota, E. First principles calculations of the electronic and chemical properties of graphene, graphane, and graphene oxide. J. Mol. Model. 2011, 17, 1133–1139. https://doi.org/10.1007/s00894-010-0818-1.
  36. Shi, G.; Araby, S.; Gibson, C.T.; Meng, Q.; Zhu, S.; Ma, J. Graphene Platelets and Their Polymer Composites: Fabrication, Structure, Properties, and Applications. Adv. Funct. Mater. 2018, 28, 1706705. https://doi.org/10.1002/adfm.201706705.
  37. Danushika, G.; Yap, P.L.; Losic, D. Quantifying the Epoxide Group and Epoxide Index in Graphene Oxide by Catalyst-Assisted Acid Titration. Anal. Chem. 2024, 96, 19339–19347. https://doi.org/10.1021/acs.analchem.4c03286.
  38. Standardization ISO 3001:1999; Plastics—Epoxy Compounds—Determination of Epoxy Equivalent. IOS: Geneva, Switzerland, 1999.
  39. Yap, P.L.; Kabiri, S.; Tran, D.N.H.; Losic, D. Multifunctional Binding Chemistry on Modified Graphene Composite for Selective and Highly Efficient Adsorption of Mercury. ACS Appl. Mater. Interfaces 2019, 11, 6350–6362. https://doi.org/10.1021/acsami.8b17131.
  40. Çiplak, Z.; Yildiz, N.; Çalimli, A. Investigation of Graphene/Ag Nanocomposites Synthesis Parameters for Two Different Synthesis Methods. Fuller. Nanotub. Carbon Nanostructures 2015, 23, 361–370. https://doi.org/10.1080/1536383X.2014.894025.
  41. Lin, J.; Peng, Z.; Liu, Y.; Ruiz-Zepeda, F.; Ye, R.; Samuel, E.L.G.; Yacaman, M.J.; Yakobson, B.I.; Tour, J.M. Laser-induced porous graphene films from commercial polymers. Nat. Commun. 2014, 5, 5714
  42. Van Pelt, A.H.; Simakova, O.A.; Schimming, S.M.; Ewbank, J.L.; Foo, G.S.; Pidko, E.A.; Hensen, E.J.M.; Sievers, C. Stability of functionalized activated carbon in hot liquid water. Carbon 2014, 77, 143–154.
  43. Goertzen, S.L.; Thériault, K.D.; Oickle, A.M.; Tarasuk, A.C.; Andreas, H.A. Standardization of the Boehm titration. Part I. CO2 expulsion and endpoint determination. Carbon 2010, 48, 1252–1261.
  44. Ederer, J. Quantitative determination of acidic groups in functionalized graphene by direct titration. React. Funct. Polym. 2016, 103, 44–53.
  45. Schönherr, J.; Buchheim, J.R.; Scholz, P.; Adelhelm, P. Boehm Titration Revisited (Part I): Practical Aspects for Achieving a High Precision in Quantifying Oxygen-Containing Surface Groups on Carbon Materials. C 2018, 4, 21.
  46. Zhang, Z. Modified potentiometric titration method to distinguish and quantify oxygenated functional groups on carbon materials by pKa and chemical reactivity. Carbon 2020, 166, 436–445.
  47. Kim, Y.S.; Yang, S.J.; Lim, H.J.; Kim, T.; Park, C.R. A simple method for determining the neutralization point in Boehm titration regardless of the CO2 effect. Carbon 2012, 50, 3315–3323.
  48. Morgunov, A.N.; Perchenko, A.A. Kinetics of saponification of ?-alkylbutyrolactones by aqueous Na2Co3 solution. Chem. Technol. Fuels Oils 1978, 14, 585–587.
  49. Zhang, Y.; Wen, G.; Fan, S.; Chu, Y.; Li, S.; Xu, B.; Zhang, J. Phenolic hydroxyl functionalized partially reduced graphene oxides for symmetric supercapacitors with significantly enhanced electrochemical performance. J. Power Sources 2019, 435, 226799. https://doi.org/10.1016/j.jpowsour.2019.226799.
  50. Dreyer, D.R.; Park, S.; Bielawski, C.W.; Ruoff, R.S. The chemistry of graphene oxide. Chem. Soc. Rev. 2010, 39, 228–240. https://doi.org/10.1039/B917103G.
  51. Lerf, A.; He, H.; Forster, M.; Klinowski, J. Structure of Graphite Oxide Revisited. J. Phys. Chem. B 1998, 102, 4477–4482. https://doi.org/10.1021/jp9731821.
  52. Kumar, A.; Panda, G. Magnesium chloride (MgCl2) catalyzed highly regioselective C-3 ring opening of 2,3 epoxy alcohols by N-nucleophile. Tetrahedron Lett. 2021, 70, 153013. https://doi.org/10.1016/j.tetlet.2021.153013.
  53. Guerrero-Contreras, J.; Caballero-Briones, F. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method. Mater. Chem. Phys. 2015, 153, 209–220. https://doi.org/10.1016/j.matchemphys.2015.01.005.