One step GO/DTES co-deposition on steels: Electro-induced fabrication and characterization of thickness-controlled coatings

- A new GO/DTES coating was fabricated by a one-step electro-induced co-deposition process.
- Enhanced corrosion-resistant and thickness-controlled GO/DTES coatings were evaluated by EIS approaches.
- Electro-induced assembly mechanism of covalent bonds between the silano, GO and metal was revealed.
- A quantitative deposition-thickness mathematical approach was exploited to optimize the process parameters.

A one-step co-deposition (electro induced) process was used to develop graphene oxide/dodecyltriethoxysilane (GO/DTES) coatings with enhanced protection performance, as well as controlled thickness. The scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM) and X-ray photoelectron spectroscope (XPS) suggested the successful electrochemical synthesis and the inclusion of GO. XPS results and the observation of the strong absorption peak corresponding to COO groups in the diffuse reflectance infrared Fourier transform spectroscope (DRIFT) indicated the covalent bonding and assembly mechanism of OH and COOH groups between the GO and silanol. This revealed the intrinsic reasons for preparing the more compact GO/DTES coatings. Results from the electrochemical impedance spectroscopy (EIS) showed that when the deposition potential and duration were optimized to about −0.8 V and 300 s, respectively, the GO/DTES samples with the maximum average thickness over 400 nm possessed the enhanced corrosion resistance. Analyses on corrosion SEM morphology and energy dispersive X-ray spectroscope (EDX), the long term 3.5% NaCl solution immersion for 480 h, the water contact angle upping to 110°, micro tribology and the adhesion experimental results further proved that there is an improved protection performance of those GO/DTES samples. The enhanced properties of these GO/DTES coatings can be ascribed to the GO doping and the controlled high thickness, inspiring a practical approach towards the fabrication of GO-based protection materials.

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