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Corrosion resistance and photocatalytic activity evaluation of electrophoretically deposited TiO 2 -rGO nanocomposite on 316L stainless steel substrate

Azadeh, M ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ceramint.2019.04.071
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. TiO 2 -rGO nanocomposite coatings were obtained by electrophoretic deposition (EPD) technique of TiO 2 nanoparticles and graphene oxide (GO) on stainless steel substrate. First, GO particles were synthesized using a modified Hummers' method. GO was reduced electrochemically to form a coating in the presence of nano-sized TiO 2 particles. The influences of different parameters such as GO concentration, coupling co-electro-deposition parameters (electrophoretic duration and voltage) on thickness, surface morphology and, corrosion behavior of the as-synthesized TiO 2 -rGO nanocomposite coatings were systematically surveyed. The morphology and microstructure were investigated by field emission scanning electron microscopy (FE-SEM), Raman spectra and X-ray diffraction (XRD) techniques. Atomic force microscopy (AFM) was harnessed to evaluate the topography of the as-prepared GO powder. The bonding characteristics of as-synthesized and as-reduced GO were examined after deposition, by Energy Dispersive Analysis of X-Ray (EDX) and Fourier-transform infrared spectroscopy (FT-IR). Corrosion behavior of coatings and that of the pure TiO 2 layer were evaluated by electrochemical impedance spectroscopy (EIS) and polarization techniques (by applying potentiodynamic polarization spectroscopy (PDS)). Detailed SEM studies showed that increasing EPD voltage brings about a coating with increased porosity and microcracks with higher thickness. In addition to that, the presence of rGO reduced corrosion current density (i corr ) and shifted corrosion potential (E corr ) toward more noble values in 3.5% NaCl at room temperature. Also, Analyses revealed that the optimum electrophoretically synthesized coating was obtained at GO concentration of 1 g/L, 30 V and 30 min at room temperature. The corrosion current density of the corresponding coating was remediated up to 0.2 μA cm −2 , which means an anti-corrosion ability of about 30 times compared to TiO 2 -coated and bare 316L stainless steel. The results of impedance spectroscopic studies demonstrated that this coating renders as a barrier layer and resistance increased from 2.95 KΩ cm 2 for TiO 2 -coated layer to 10.49 KΩ cm 2 for the optimized layer. © 2019 Elsevier Ltd and Techna Group S.r.l
  6. Keywords:
  7. TiO 2 ; Wear resistance ; Atomic force microscopy ; Austenitic stainless steel ; Corrosion ; Corrosion resistance ; Corrosion resistant coatings ; Corrosive effects ; Deposition ; Electrochemical corrosion ; Electrochemical impedance spectroscopy ; Electrophoresis ; Electrophoretic coatings ; Enamels ; Field emission microscopes ; Fourier transform infrared spectroscopy ; Graphene ; Microalloyed steel ; Microcracks ; Nanocomposites ; Photocatalytic activity ; Polarization ; Scanning electron microscopy ; Sodium chloride ; Spectroscopic analysis ; Surface morphology ; TiO2 nanoparticles ; Titanium dioxide ; Topography ; Bonding characteristics ; Corrosion current densities ; Electrophoretic deposition techniques ; Energy dispersive analysis of X-rays ; Field emission scanning electron microscopy ; Fourier transform infra red (FTIR) spectroscopy ; Stainless steel substrates ; TiO2 ; Steel corrosion
  8. Source: Ceramics International ; Volume 45, Issue 11 , 2019 , Pages 13747-13760 ; 02728842 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S0272884219308922