Investigation of Inhibition Effect of 1-(aminoN-phenyl methanethio) thiosemicarbazide on Carbon Steel Corrosion in Acidic Solution: Adsorption Behavior Study using Fast Fourier Transform Continuous Cyclic Voltammetry

Corrosion inhibition of carbon steel in 1.0 M HCl solution by 1-(aminoNphenylmethanethio)thiosemicarbazide (APTSC) was investigated by potentiodynamic polarization, Electrochemical Impedance Spectroscopy (EIS) and Fast Fourier Transform Continuous Cyclic Voltammetry (FFTCCV). Polarization studies revealed that APTSC is a mixed-type corrosion inhibitor. The results showed that the inhibition efficiency increased with increasing the inhibitor concentration and maximum inhibition was obtained 92% at 1.0×10−3 M of APTSC. EIS results confirmed that the inhibitor is adsorbed on the carbon steel surface, leading to increase the polarization resistance (Rp) and decrease the doublelayer capacitance. FFTCCV confirmed that the addition of inhibitor into the HCl solution decreased the rate of carbon steel corrosion. Also, it was found that after about 3400 s, the inhibitor reaches to its maximum surface coverage.