Experimental and Computational Studies of a Novel Metal Oxide Nanoparticle/Conducting Polymer Nanocomposite (TiO<sub>2</sub>/PVP) as a Corrosion Inhibitor on Low-Carbon Steel in Diprotic Acidic Medium
Himanshi Bairagi, Priya Vashishth, Rajni Narang, Sudhish Kumar Shukla, Bindu Mangla
Abstract
The titanium dioxide/poly(vinylpyrrolidone) (TiO 2 /PVP) nanocomposite was prepared by in situ polymerization using different concentrations of poly(vinylpyrrolidone). The titanium dioxide nanoparticles were synthesized by a co-precipitation method using titanium tetraisopropoxide (TTIP) and ethanol (C 2 H 5 OH). The particle size of the synthesized TiO 2 nanoparticles and TiO 2 /PVP nanocomposite was determined through the X-ray diffraction (XRD) technique, and ultraviolet–visible (UV–vis) and Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy/energy dispersive X-ray (SEM/EDAX) were used to characterize the synthesized nanoparticles (NPs) and nanocomposite (NC). The corrosion inhibition of low-carbon steel in 0.5 N sulfuric acid (H 2 SO 4 ) by titanium dioxide nanoparticles, poly(vinylpyrrolidone), and their nanocomposite was investigated by gravimetric and electrochemical methods. According to the results of potentiodynamic polarization curves and alternative current (AC) impedance analysis, all inhibitors followed mixed-type inhibition and formed a monolayer on the surface. The gravimetric study demonstrated that all the investigated inhibitors followed Langmuir monolayer adsorption. Experimental data from atomic force microscopy (AFM) and quantum chemical analysis also showed that the protective film developed by the prepared nanocomposite exhibited excellent corrosion resistance that was superior to that of other microconstituents.