Theoretical and experimental studies of dried marjoram leaves extract as green inhibitor for corrosion protection of steel substrate in acidic solution

Novel use of kitchen waste: protection of boiler quality steel from corrosion in acidic media using onion waste

An eco-friendly approach to inhibit the corrosion of boiler quality (BQ) steel by onion waste in acidic media was investigated. The extract from onion peel was characterized using the conventional extraction method and was characterized using HPLC. The efficacy of the onion peel extract (OPE) as a green corrosion inhibitor was studied using the weight loss method and a variety of electrochemical techniques, including open-circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The Tafel polarization revealed that at 200 mg L^-1 of onion peel extract (OPE), corrosion current density was reduced maximum in both 1 (M) HCl and 0.5 (M) H₂SO₄ media. From the electrochemical impedance spectroscopy studies, the maximum inhibition efficiencies of 91.30% and 90.71% were found at 200 mg L^-1 in 1 (M) HCl and 0.5 (M) H₂SO₄, respectively. The Langmuir isotherm was determined to be the best-fitting model, and the thermodynamic parameter, such as free energy Δ G ads ∘ , was computed, which indicated the physisorption of OPE onto the BQ surface. In theoretical investigations, density functional theory DFT was used to determine the adsorption efficiency and reactive sites of the OPE molecule by exploring various quantum chemical parameters.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11696-022-02549-7.

Comparative Evaluation of Anticorrosive Properties of Mahaleb Seed Extract on Carbon Steel in Two Acidic Solutions

Aqueous extract solution of Mahaleb seed (ASMS) was prepared using a simple and safe method. ASMS was tested to examine its potential to act as a green corrosion inhibitor for preventing the dissolution of Carbon steel in highly concentrated corrosive 2 M H₂SO₄ and 2 M H₃PO₄ using an electrochemical polarization Tafel plot and electrochemical impedance spectroscopy. ASMS provided a slight increase in the inhibition efficiency of H₃PO₄ (89%) compared with H₂SO₄ (86%). Fourier transform infrared spectroscopy (FTIR) and electronic scanning microscopy (SEM) were used to prove that adsorption of ASMS occurred on the metal surface. The thermodynamic adsorption and thermodynamic activation parameters were calculated at a range of concentrations and temperatures. The physisorption of ASMS followed the Langmuir adsorption isotherm (R² = 0.98). Finally, the role of ASMS as a protection mechanism was discussed.