Experimental and Computational Studies of a Novel Metal Oxide Nanoparticle/Conducting Polymer Nanocomposite (tio2/pvp) As a Corrosion Inhibitor on Low-Carbon Steel in Diprotic Acidic Medium

The titanium dioxide/poly(vinylpyrrolidone) (TiO2/PVP)nanocomposite was prepared by in situ polymerization using differentconcentrations of poly(vinylpyrrolidone). The titanium dioxide nanoparticleswere synthesized by a co-precipitation method using titanium tetraisopropoxide(TTIP) and ethanol (C2H5OH). The particle sizeof the synthesized TiO2 nanoparticles and TiO2/PVP nanocomposite was determined through the X-ray diffraction (XRD)technique, and ultraviolet-visible (UV-vis) and Fouriertransform infrared (FT-IR) spectroscopy and scanning electron microscopy/energydispersive X-ray (SEM/EDAX) were used to characterize the synthesizednanoparticles (NPs) and nanocomposite (NC). The corrosion inhibitionof low-carbon steel in 0.5 N sulfuric acid (H2SO4) by titanium dioxide nanoparticles, poly(vinylpyrrolidone), andtheir nanocomposite was investigated by gravimetric and electrochemicalmethods. According to the results of potentiodynamic polarizationcurves and alternative current (AC) impedance analysis, all inhibitorsfollowed mixed-type inhibition and formed a monolayer on the surface.The gravimetric study demonstrated that all the investigated inhibitorsfollowed Langmuir monolayer adsorption. Experimental data from atomicforce microscopy (AFM) and quantum chemical analysis also showed thatthe protective film developed by the prepared nanocomposite exhibitedexcellent corrosion resistance that was superior to that of othermicroconstituents.