Journal of Sol-Gel Science and Technology

, Volume 81, Issue 2, pp 556–569 | Cite as

Hydrothermal-assisted sol–gel synthesis of Cd-doped TiO2 nanophotocatalyst for removal of acid orange from wastewater

Original Paper: Sol-gel and hybrid materials for catalytic, photoelectrochemical and sensor applications


This research is based on synthesis of titania (TiO2) nanophotocatalyst followed by cadmium (Cd) doping to activate the photocatalyst in visible part of the light spectrum. Therefore, the Cd–TiO2 nanophotocatalyst was synthesized in various Cd/Ti molar ratios of 0, 0.05, 0.1, and 0.15 using hydrothermal-assisted sol–gel method. The characterization analyses of X-ray diffraction, field emission scanning electron microscopy, brunauer-emmett-teller, diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric-derivative thermogravimetric, transmission electron microscopy, and energy dispersive X-ray were carried out to evaluate the physical, chemical, and optical properties of the catalysts. The X-ray diffraction analysis resulted a decrease in the crystallinity due to cadmium doping. Field emission scanning electron microscopy images have confirmed the nano-sized structure of the catalysts. The analysis also has demonstrated particle size distribution enhancement with a meaningful low average particle size for Cd/TiO2 (0.15) sample. This sample has represented the highest brunauer-emmett-teller surface area. According to energy dispersive X-ray dot mapping analysis, no aggregation was detected on the catalyst surface. Diffuse reflectance spectroscopy analysis has indicated a moderate decrease in band gap, after Cd loading. The photocatalytic degradation of acid orange 7 dye from the synthetic wastewater was carried out to evaluate the photocatalytic activity. The most effective parameters on the process, such as pH, catalyst loading, and dye concentration, were investigated. According to the characterization analyses and degradation tests, Cd/TiO2 (0.15) was selected as a sample having best structural properties and photocatalytic activity. Finally, the experiments resulted the optimum conditions of pH = 2, catalyst loading of 1 g/L, and dye concentration of 10 mg/L, indicating 95 % of dye degradation after 120 min of experiment.

Graphical Abstract

The electron–hole pair generation via transition of electron between the valence and conduction bands (band gap) is the fundamental of any photocatalytic process. After Cd doping, the conduction band position shifts toward the valence band. Then, a valence electron in narrow band gap photocatalyst needs lower energy of light to transfer to conduction band, it means that using light in higher wavelengths (visible light spectra) will be available. In photocatalytic wastewater treatment process, degradation occurs in two ways: the first mechanism is direct oxidation-reduction through electron–hole generation, and the second one would be the oxidation through produced reactive species such as hydroxyl radicals, this route of reaction organizes the major part of wastewater treatment. Open image in new window


Cd/TiO2 Sol-gel Hydrothermal Nanophotocatalyst Wastewater treatment 



The authors gratefully acknowledge Sahand University of Technology for the financial support of the research, as well as Iran Nanotechnology Initiative Council for complementary financial supports.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Sonune A, Ghate R (2004) Developments in wastewater treatment methods. Desalination 167:55–63CrossRefGoogle Scholar
  2. 2.
    Qu X, Alvarez PJ, Li Q (2013) Applications of nanotechnology in water and wastewater treatment. Water Res 47(12):3931–3946CrossRefGoogle Scholar
  3. 3.
    Chong MN, Jin B, Chow CW, Saint C (2010) Recent developments in photocatalytic water treatment technology: a review. Water Res 44(10):2997–3027CrossRefGoogle Scholar
  4. 4.
    Gogate PR, Pandit AB (2004) A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions. Adv Environ Res 8(3):501–551CrossRefGoogle Scholar
  5. 5.
    Zaleska A (2008) Doped-TiO2: a review. Recent Pat Eng 2(3):157–164CrossRefGoogle Scholar
  6. 6.
    Pelaez M, Nolan NT, Pillai SC, Seery MK, Falaras P, Kontos AG, Dunlop PS, Hamilton JW, Byrne JA, O’Shea K (2012) A review on the visible light active titanium dioxide photocatalysts for environmental applications. Appl Catal B: Environ 125:331–349CrossRefGoogle Scholar
  7. 7.
    Alinsafi A, Evenou F, Abdulkarim E, Pons M-N, Zahraa O, Benhammou A, Yaacoubi A, Nejmeddine A (2007) Treatment of textile industry wastewater by supported photocatalysis. Dyes Pigm 74(2):439–445CrossRefGoogle Scholar
  8. 8.
    Wang C, Liu H, Qu Y (2013) TiO2-based photocatalytic process for purification of polluted water: bridging fundamentals to applications. J Nanomater 2013:14Google Scholar
  9. 9.
    Asahi R, Morikawa T, Irie H, Ohwaki T (2014) Nitrogen-doped titanium dioxide as visible-light-sensitive photocatalyst: designs, developments, and prospects. Chem Rev 114(19):9824–9852CrossRefGoogle Scholar
  10. 10.
    Hsieh C-T, Fan W-S, Chen W-Y, Lin J-Y (2009) Adsorption and visible-light-derived photocatalytic kinetics of organic dye on Co-doped titania nanotubes prepared by hydrothermal synthesis. Sep Purif Technol 67(3):312–318CrossRefGoogle Scholar
  11. 11.
    Karunakaran C, Vijayabalan A, Manikandan G, Gomathisankar P (2011) Visible light photocatalytic disinfection of bacteria by Cd–TiO2. Catal Commun 12(9):826–829CrossRefGoogle Scholar
  12. 12.
    Gouvea CA, Wypych F, Moraes SG, Duran N, Nagata N, Peralta-Zamora P (2000) Semiconductor-assisted photocatalytic degradation of reactive dyes in aqueous solution. Chemosphere 40(4):433–440CrossRefGoogle Scholar
  13. 13.
    Dimitriev Y, Ivanova Y, Iordanova R (2008) History of sol-gel science and technology. J Univ Chem Technol Metallurgy 43(2):181–192Google Scholar
  14. 14.
    Gonzalez RD, Lopez T, Gomez R (1997) Sol–gel preparation of supported metal catalysts. Catal Today 35(3):293–317CrossRefGoogle Scholar
  15. 15.
    Colón G, Hidalgo M, Navío J, Melián EP, Díaz OG, Rodríguez JD (2008) Highly photoactive ZnO by amine capping-assisted hydrothermal treatment. Appl Catal B: Environ 83(1):30–38CrossRefGoogle Scholar
  16. 16.
    Melián EP, Díaz OG, Rodríguez JD, Colón G, Navío J, Peña JP (2012) Effect of hydrothermal treatment on structural and photocatalytic properties of TiO2 synthesized by sol–gel method. Appl Catal A: Gen 411:153–159CrossRefGoogle Scholar
  17. 17.
    Scherrer P (1918) Bestimmung der Grösse und der inneren Struktur von Kolloidteilchen mittels Röntgenstrahlen. Nachrichten von der Gesellschaft der Wissenschaften zu Gottingen 26:98–100Google Scholar
  18. 18.
    Ba-Abbad MM, Kadhum AAH, Mohamad AB, Takriff MS, Sopian K (2013) Visible light photocatalytic activity of Fe3+-doped ZnO nanoparticle prepared via sol–gel technique. Chemosphere 91(11):1604–1611CrossRefGoogle Scholar
  19. 19.
    Lan NT, Phan LG, Hoang LH, Huan BD, Van Hong L, Anh TX, Chinh HD (2016) Hydrothermal synthesis, structure and photocatalytic properties of La/Bi Co-doped NaTaO3. Mater Trans 57(1):1–4CrossRefGoogle Scholar
  20. 20.
    Bao N, Niu J-J, Li Y, Wu G-L, Yu X-H (2013) Low-temperature hydrothermal synthesis of N-doped TiO2 from small-molecule amine systems and their photocatalytic activity. Environ Technol 34(21):2939–2949CrossRefGoogle Scholar
  21. 21.
    Abdollahifar M, Haghighi M, Babaluo AA, Khajeh Talkhoncheh S (2016) Sono-synthesis and characterization of bimetallic Ni-Co/Al2O3-MgO nanocatalyst: effects of metal content on catalytic properties and activity for hydrogen production via CO2 reforming of CH4. Ultrason Sonochem 31:173–183CrossRefGoogle Scholar
  22. 22.
    Parvas M, Haghighi M, Allahyari S (2014) Degradation of phenol via wet-air oxidation over CuO/CeO2-ZrO2 nanocatalyst synthesized employing ultrasound energy: physicochemical characterization and catalytic performance. Environ Technol 35(9):1140–1149CrossRefGoogle Scholar
  23. 23.
    Talati A, Haghighi M, Rahmani F (2016) Impregnation vs. coprecipitation dispersion of Cr over TiO2 and ZrO2 used as active and stable nanocatalysts in oxidative dehydrogenation of ethane to ethylene by carbon dioxide. RSC Adv 6(50):44195–44204CrossRefGoogle Scholar
  24. 24.
    Khoshbin R, Haghighi M, Asgari N (2013) Direct synthesis of dimethyl ether on the admixed nanocatalysts of CuO–ZnO–Al2O3 and HNO3-modified clinoptilolite at high pressures: surface properties and catalytic performance. Mater Res Bull 48(2):767–777CrossRefGoogle Scholar
  25. 25.
    Aghaei E, Haghighi M (2015) Effect of crystallization time on properties and catalytic performance of nanostructured SAPO-34 molecular sieve synthesized at high temperatures for conversion of methanol to light olefins. Powder Technol 269:358–370CrossRefGoogle Scholar
  26. 26.
    Boccuzzi F, Chiorino A, Manzoli M (2003) FTIR study of methanol decomposition on gold catalyst for fuel cells. J Power Sources 118(1):304–310CrossRefGoogle Scholar
  27. 27.
    Cheng X, Yu X, Xing Z, Wan J (2012) Enhanced photocatalytic activity of nitrogen doped TiO2 anatase nano-particle under simulated sunlight irradiation. Energy Procedia 16:598–605CrossRefGoogle Scholar
  28. 28.
    Tauc J, Grigorovici R, Vancu A (1966) Optical properties and electronic structure of amorphous germanium. Phys Status Solidi (B) 15(2):627–637CrossRefGoogle Scholar
  29. 29.
    Manikandan A, Hema E, Durka M, Selvi MA, Alagesan T, Antony SA (2015) Mn2+ doped NiS (MnxNi1−xS: x=0.0, 0.3 and 0.5) nanocrystals: structural, morphological, opto-magnetic and photocatalytic properties. J Inorg Organomet Polym Mater 25(4):804–815CrossRefGoogle Scholar
  30. 30.
    Wu H, Zhang Z (2011) High photoelectrochemical water splitting performance on nitrogen doped double-wall TiO2 nanotube array electrodes. Int J Hydrogen Energy 36(21):13481–13487CrossRefGoogle Scholar
  31. 31.
    Khataee A, Zarei M, Moradkhannejhad L, Nourie S, Vahid B (2013) Nitrogen doping of commercial TiO2 nanoparticles for enhanced photocatalytic degradation of dye under visible light: central composite design approach. Adv Chem Lett 1(1):24–31CrossRefGoogle Scholar
  32. 32.
    Daneshvar N, Salari D, Khataee A (2003) Photocatalytic degradation of azo dye acid red 14 in water: investigation of the effect of operational parameters. J Photochem Photobiol A: Chem 157(1):111–116CrossRefGoogle Scholar
  33. 33.
    Xiao Q, Zhang J, Xiao C, Si Z, Tan X (2008) Solar photocatalytic degradation of methylene blue in carbon-doped TiO2 nanoparticles suspension. Sol Energy 82(8):706–713CrossRefGoogle Scholar
  34. 34.
    Ahmed S, Rasul M, Brown R, Hashib M (2011) Influence of parameters on the heterogeneous photocatalytic degradation of pesticides and phenolic contaminants in wastewater: a short review. J Environ Manage 92(3):311–330CrossRefGoogle Scholar
  35. 35.
    Jaimes-Ramírez R, Vergara-Sánchez J, Silva-Martínez S (2012) Solar assisted degradation of acid orange 7 textile dye in aqueous solutions by Ce-doped TiO2. Mex J Sci Res 1:42–55Google Scholar
  36. 36.
    Prabha S, Chandraboss V, Kamalakannan J, Senthilvelan S (2015) Activated charcoal supported cadmium doped TiO2 for photocatalytic and antibacterial applications. Int Lett Chem Phy Astron 5(2):108CrossRefGoogle Scholar
  37. 37.
    Hao H-Y, He C-X, Tian B-Z, Zhang J-L (2009) Study of photocatalytic activity of Cd-doped mesoporous nanocrystalline TiO2 prepared at low temperature. Res Chem Intermediat 35(6-7):705–715CrossRefGoogle Scholar
  38. 38.
    Yalçın Y, Kılıç M, Çınar Z (2010) Fe+3-doped TiO2: a combined experimental and computational approach to the evaluation of visible light activity. Appl Catal B: Environ 99(3):469–477Google Scholar
  39. 39.
    Lu J, Su F, Huang Z, Zhang C, Liu Y, Ma X, Gong J (2013) N-doped Ag/TiO2 hollow spheres for highly efficient photocatalysis under visible-light irradiation. RSC Adv 3(3):720–724CrossRefGoogle Scholar
  40. 40.
    Song K, Zhou J, Bao J, Feng Y (2008) Photocatalytic activity of (copper, nitrogen)‐codoped titanium dioxide nanoparticles. J Am Ceram Soc 91(4):1369–1371CrossRefGoogle Scholar
  41. 41.
    Konstantinou IK, Albanis TA (2004) TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations: a review. Appl Catal B: Environ 49(1):1–14CrossRefGoogle Scholar
  42. 42.
    Teh CM, Mohamed AR (2011) Roles of titanium dioxide and ion-doped titanium dioxide on photocatalytic degradation of organic pollutants (phenolic compounds and dyes) in aqueous solutions: a review. J Alloy Compd 509(5):1648–1660CrossRefGoogle Scholar
  43. 43.
    Kudo A, Miseki Y (2009) Heterogeneous photocatalyst materials for water splitting. Chem Soc Rev 38(1):253–278CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Chemical Engineering FacultySahand University of TechnologyTabrizIran
  2. 2.Reactor and Catalysis Research Center (RCRC)Sahand University of TechnologyTabrizIran

Personalised recommendations