Novel Synthesis of SiC-SiO2 Nanotubes from Cinachyrella sp. and Its Improvement of the Corrosion Resistance of Low Carbon Steel in 3.5% NaCl Water Solution

Abstract Coat synthesis of silicon carbide and composites of Si derivatives is a challenge for high-quality thin film applications, including corrosion resistance industries. A novel fabrication process of silicon carbide-silicon dioxide nanotube composites (SCDNTs) was developed by a solid reaction of silicon-carbon (marine sponge Cinachyrella sp .) resources. Trimetallic catalyst (Fe/Ni/Zr) supported on different Al 2 O 3 media with heating in an argon flow was used to prepare SCDNTs composite. A higher crystallinity degree of the nanocomposites is attained at a heating temperature of 1200 °C as a suitable starting temperature to have a reasonable degree of crystallinity. XRD analysis of the prepared composite showed the presence of polycrystalline silicon dioxide and two phases of silicon carbide; 3C-SiC and 6H-SiC. TEM analysis showed the presence of silicon carbide's cubic and hexagonal structures embedded into silicon dioxide nanotubes. FTIR analysis confirmed the XRD and TEM analyses through the presence of the functional groups related to Si-Si, Si-O and Si-C. The SCDNTs spin coating process on LWS was optimized at 1000 rpm. Varying thin coatings of up to 5 layers of SCDNTs were prepared low steel substrate to evaluate its corrosion behavior in a 3.5% NaCl solution. Five-layer SCDNTs composite coating on LCS was the favorable coating as obtained from the electrochemical measurements ensured a corrosion inhibition efficiency of 92.5% and corrosion rate of 63.98 mm/y. XRD spectra and stereomicroscope were used to evaluate the surface of LWS coated with SCDNTs before and after corrosion test. Graphical Abstract