Phytochemicals as steel corrosion inhibitor: an insight into mechanism

Abstract

Corrosion is a spontaneous process that adversely affects strength and quality of economically vital materials including steel. Plant extracts are emerging as renewable, low cost and eco-friendly alternate to existing toxic chemical corrosion inhibitors. Physisorption, Chemisorption and retrodonation are the main mechanism of corrosion inhibition by plant extracts. Different functional groups of phytochemicals namely carbohydrate, lipids, terpenoids, phenolic acids, alkaloids and other nitrogen containing metabolites participate in physisorption, chemisorption and retrodonation with steel surface in presence of HCl and H2SO4 to act as corrosion inhibitors. Exact mechanism of inhibition depends upon presence of such phytochemical in the plant extracts.

Expired flunarizine hydrochloride as corrosion inhibitors for Q235 steel in hydrochloric acid medium: Experimental and computational investigation

“…As reported by previous work, the electrostatic interaction of protonation inhibitor molecules with pre-adsorbed chloride ions is physical adsorption. 53,54 The interaction between the non-shared electron pair of heteroatom N and the vacancy d-orbital of the iron atom is chemisorption 55,56 ; Furthermore, the donor-receptor interacts between the π-electron of the aromatic ring and the d-orbital of the iron vacancy. 57 As reported by Qiang et al, 58,59 the barrier efficiency of adsorbed layer on steel surface exhibits superior corrosion protection for steel surface.…”

Potential Applications of Ginger Rhizomes as a Green Biomaterial: A Review

“…According to the literature [53,54,59], ginger extract was classified as a mixed-type corrosion inhibitor, demonstrating inhibition effect via Figure 3. Mechanism of corrosion inhibition by ginger extract; physisorption through electrostatic interaction and chemisorption between heteroatoms of aromatic ring and vacant d-orbital of metal [58] the formation of carbonaceous organic film on the metal surface. Base on analyses of liquid chromatography-mass spectrometry (LCMS), X-ray photoelectron spectroscopy (XPS), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR); the carbonaceous film could be composed of different phenolic compounds like 6-gingerol and curcumin [53].…”

Organo-metallic electrolyte additive for regulating hydrogen evolution and self-discharge in Mg–air aqueous battery

“…It should be mentioned there is a huge chance that (i) hydrophobicity of the surfactant used could contribute to building the barrier, (ii) silicon and oxygen presence could initiate a chemical bond with magnesium. 65,66 The combined anti-corrosive and electrocatalytic behaviour of D3 enables rapid ion migration, enhancing the anodic performance. Perhaps, the discharge capacity and shelf-life of the Mg-air battery have been improved through the addition of D3.…”