, Volume 9, Issue 5, pp 623–631 | Cite as

Efficient and Cost-effective Photoelectrochemical Degradation of Dyes in Wastewater over an Exfoliated Graphite-MoO3 Nanocomposite Electrode

  • Onoyivwe Monday Ama
  • Neeraj Kumar
  • Feyisayo Victoria Adams
  • Suprakas Sinha Ray
Original Research


Herein, we prepared hexagonal MoO3 (h-MoO3) nanorods by homogenous co-precipitation and utilized them to fabricate a composite h-MoO3-exfoliated graphite (EG) electrode. The above composite was characterized by scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and UV-Vis spectroscopy, and used for the degradation of cationic (methylene blue, MB) and anionic (methyl red, MR) dyes in synthetic wastewater. The efficiency of this degradation was assessed by UV-Vis spectroscopy and electrochemical techniques. Good dispersion of h-MoO3 in EG decreased the electron-hole recombination rate and enhanced the photon absorption efficiency of the EG-MoO3 electrode, which therefore exhibited a higher dye photodegradation efficiency than the bare EG one. Specifically, the efficiencies of 180-min MB photodegradation over EG and EG-MoO3 electrodes were 66.9 and 88.55%, respectively, whereas the corresponding values for MR were 68.0 and 92.22%, respectively, i.e., MR was degraded more effectively than MB. Furthermore, photoelectrochemical oxidation was shown to be more efficient than purely photolytic and electrochemical oxidation, which, together with the ease of preparation, low cost, and high photoactivity/stability of the fabricated nanocomposite electrode makes it potentially suitable for industrial wastewater treatment.

Graphical abstract


Exfoliated graphite H-MoO3 Electrode Photoelectrochemical Dye degradation 


Funding Information

The study is financially supported by the National Centre for Nano-structured Materials, CSIR Pretoria, PDRF University of Johannesburg and National Research Foundation, South Africa.


  1. 1.
    M. Khajeh, S. Laurent, K. Dastafkan, Nanoadsorbents: Classification, preparation, and applications (with emphasis on aqueous media). Chem. Rev. 113, 7728−7768 (2013)CrossRefGoogle Scholar
  2. 2.
    N. Kumar, S.S. Ray, J.C. Ngila, Ionic liquid-assisted synthesis of Ag/Ag2Te nanocrystals via a hydrothermal route for enhanced photocatalytic performance. New J. Chem. 41(23), 14618–14626 (2017)CrossRefGoogle Scholar
  3. 3.
    N. Kumar, L. Reddy, J.C. Ngila, V. Parashar, Controlled synthesis of microsheets of ZnAl layered double hydroxides hexagonal nanoplates for efficient removal of Cr(VI) ions and anionic dye from water. J. Environ. Chem. Eng. 5, 1718−1731 (2017)Google Scholar
  4. 4.
    R. Andreozzi, V. Caprio, A. Insola, R. Marotta, Advanced oxidation processes (AOP) for water purification and recovery. Catal. Today 53, 51−59 (1999)CrossRefGoogle Scholar
  5. 5.
    Q. Gui, Z. Xu, H. Zhang, C. Cheng, X. Zhu, M. Yin, Enhanced photoelectrochemical water splitting performance of anodic TiO2 nanotube arrays by surface passivation. ACS Appl. Mater. Interfaces 6(19), 17053–17058 (2014)CrossRefGoogle Scholar
  6. 6.
    C.A. Martinez-Huitle, S. Ferro, Electrochemical oxidation of organic pollutants for the wastewater treatment: direct and indirect processes. Chem. Soc. Rev. 35, 1324−1340 (2006)CrossRefGoogle Scholar
  7. 7.
    A. Asghar, A.A.A. Raman, W.M.A.W. Daud, Advanced oxidation processes for in-situ production of hydrogen peroxide/hydroxyl radical for textile wastewater treatment: a review. J. Clean. Prod. 87, 826−838 (2015)CrossRefGoogle Scholar
  8. 8.
    H. Zhang, G. Chen, D.W. Bahnemann, Photoelectrocatalytic materials for environmental applications. J. Mater. Chem. 19(29), 5089–5121 (2009)CrossRefGoogle Scholar
  9. 9.
    J.M. Herrmann, Heterogeneous photocatalysis: fundamentals and applications to the removal of various types of aqueous pollutants. Catal. Today 53, 115−129 (1999)CrossRefGoogle Scholar
  10. 10.
    A. Khademi, A.Z. Moshfegh, Growth and field emission study of molybdenum oxide nanostars. J Phy. Chem. C 113(44), 19298–19304 (2009)CrossRefGoogle Scholar
  11. 11.
    J. Wang, S. Dong, C. Yu, X. Han, J. Guo, J. Sun, An efficient MoO3 catalyst for in-practical degradation of dye wastewater under room conditions. Catal. Commun. 92, 100−104 (2017)CrossRefGoogle Scholar
  12. 12.
    X. Yu, X. Cheng, Preparation and photoelectrochemical performance of expanded graphite/TiO2 composite. Electrochim. Acta 137, 668−675 (2014)CrossRefGoogle Scholar
  13. 13.
    O.M. Ama, N. Mabuba, O.A. Arotiba, Synthesis, characterization, and application of exfoliated graphite/zirconium nanocomposite electrode for the photoelectrochemical degradation of organic dye in water. Electrocatalysis 6, 390−397 (2015)CrossRefGoogle Scholar
  14. 14.
    S. Verma, H.P. Mungse, N. Kumar, S. Choudhary, S.L. Jain, B. Sain, Graphene oxide: an efficient and reusable carbocatalyst for aza-Michael addition of amines to activated alkenes. Chem. Commun. 47(47), 12673–12675 (2011)CrossRefGoogle Scholar
  15. 15.
    W. Han, L. Ren, X. Qi, Y. Liu, X. Wei, Z. Huang, J. Zhong, Synthesis of CdS/ZnO/graphene composite with high-efficiency photoelectrochemical activities under solar radiation. Appl. Surf. Sci. 299, 12−18 (2014)CrossRefGoogle Scholar
  16. 16.
    O.M. Ama, O.A. Arotiba, Exfoliated graphite/titanium dioxide for enhanced photoelectrochemical degradation of methylene blue dye under simulated visible light irradiation. J. Electroanal. Chem. 803, 157−164 (2017)CrossRefGoogle Scholar
  17. 17.
    N. Kumar, B.P.A. George, H. Abrahamse, V. Parashar, J.C. Ngila, Sustainable one-step synthesis of hierarchical microspheres of PEGylated MoS2 nanosheets and MoO3 nanorods: their cytotoxicity towards lung and breast cancer cells. Appl. Surf. Sci. 396, 8−18 (2017)Google Scholar
  18. 18.
    A. Chithambararaj, N. Sanjini, S. Velmathi, A.C. Bose, Preparation of h-MoO3 and α-MoO3 nanocrystals: comparative study on photocatalytic degradation of methylene blue under visible light irradiation. Phys. Chem. Chem. Phys. 15(35), 14761–14769 (2013)CrossRefGoogle Scholar
  19. 19.
    B. Ntsendwana, B.B. Mamba, S. Sampath, O.A. Arotiba, Electrochemical detection of bisphenol A using graphene modified glassy carbon electrode. Int. J. Electrochem. Sci. 7, 3501–3512 (2012)Google Scholar
  20. 20.
    A. Das, B. Chakraborty, A. Sood, Raman spectroscopy of graphene on different substrates and influence of defects. Bull. Mater. Sci. 31, 579−584 (2008)Google Scholar
  21. 21.
    Q. Lai, S. Zhu, X. Luo, M. Zou, S. Huang, Ultraviolet-visible spectroscopy of graphene oxides. AIP Adv. 2, 032146 (2012)CrossRefGoogle Scholar
  22. 22.
    Z. Shen, G. Chen, Y. Yu, Q. Wang, C. Zhou, L. Hao, Y. Li, L. Heb, M. Rende, Sonochemistry synthesis of nanocrystals embedded in a MoO3–CdS core–shell photocatalyst with enhanced hydrogen production and photodegradation. J. Mater. Chem. 22(37), 19646–19651 (2012)Google Scholar
  23. 23.
    E.H. Umukoro, M.G. Peleyeju, J.C. Ngila, O.A. Arotiba, Photoelectrochemical degradation of orange II dye in wastewater at a silver–zinc oxide/reduced graphene oxide nanocomposite photoanode. RSC Adv. 6(58), 52868–52877 (2016)CrossRefGoogle Scholar
  24. 24.
    P. Wang, Y. Tang, Z. Dong, Z. Chen, T.T. Lim, Ag–AgBr/TiO2/RGO nanocomposite for visible-light photocatalytic degradation of penicillin G. J. Mater. Chem. A 1(15), 4718–4727 (2013)CrossRefGoogle Scholar
  25. 25.
    E.H. Umukoro, G.P. Moses, C.J. Ngila, O.A. Arotiba, Towards wastewater treatment: photo-assisted electrochemical degradation of 2-nitrophenol and orange II dye at a tungsten trioxide-exfoliated graphite composite electrode. Chem. Eng. J. 317, 290−301 (2017)CrossRefGoogle Scholar
  26. 26.
    M.G. Peleyeju, E.H. Umukoro, J.O. Babalola, O.A. Arotiba, Electrochemical degradation of an anthraquinonic dye on an expanded graphite-diamond composite electrode. Electrocatalysis 2, 132–139 (2016)CrossRefGoogle Scholar
  27. 27.
    E.H. Umukoro, M.G. Peleyeju, J.C. Ngila, O.A. Arotiba, Photocatalytic degradation of acid blue 74 in water using Ag–Ag2O–ZnO nanostructures anchored on graphene oxide. Solid State Sci. 51, 66−73 (2016)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Onoyivwe Monday Ama
    • 1
    • 2
  • Neeraj Kumar
    • 1
  • Feyisayo Victoria Adams
    • 3
  • Suprakas Sinha Ray
    • 1
    • 2
  1. 1.Department of Applied ChemistryUniversity of JohannesburgDoornfonteinSouth Africa
  2. 2.DST/CSIR National Centre for Nano-structured Materials, Council for Scientific and Industrial ResearchPretoriaSouth Africa
  3. 3.Department of Petroleum ChemistryAmerican University of NigeriaYolaNigeria

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