Investigation of mild steel corrosion inhibition in acidic media by Viola extract based on bulk and nanometer size.

In the present work, the inhibition performance of Viola extract based on bulk and nano size as a green corrosion inhibitor on mild steel in 0.5 M phosphoric acid and 1M hydrochloric acid solutions is investigated using different techniques (potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and Optical microscopy). The gained results demonstrated that various concentrations of Viola Extract (bulk and nano) inhibited the corrosion of the alloy in both of the acid solutions. The temperature impact on corrosion rate without/with this extract was examined. Certain thermodynamic parameters were determined based on the temperature impact on inhibition and corrosion processes. The adsorption mechanism of the extract on the alloy was explored using the Langmuir adsorption isotherm. A mixed mode of adsorption was observed, wherein the nano-sized extract in 1.0 M HCl predominantly underwent chemisorption, while the bulk-sized extract in 1.0 M HCl and both bulk and nano-sized extracts in 0.5 M H3PO4 were primarily subjected to physisorption. Scanning electron microscopy (SEM) and Optical microscopy analyses were employed to scrutinize alloys' surface morphology.

Investigation of Dracocephalum extract based on bulk and nanometer size as green corrosion inhibitor for mild steel in different corrosive media.

In recent years, green corrosion inhibitors derived from natural plant resources have garnered much interest. In the present work, at first, we investigated the corrosion behavior of mild steel (st-37) in the presence, and absence of Dracocephalum extract based on bulk size as a corrosion inhibitor in two widely used acidic environments (0.5 M H2SO4, and 1.0 M HCl), at room temperature. Then, we used Dracocephalum extract based on nanometer size to reduce the optimal concentration of inhibitor, increase the corrosion resistant, and efficiency. Dracocephalum extract does not contain heavy metals or other toxic compounds, and also good characteristics such as low cost, eco-friendly, and widespread availability, make it suitable nature candidate as an environmentally safe green inhibitor. The anticorrosive behavior was assessed using electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PP). In all of the studies, the inhibitory efficiency (IE%) increased as the extract dose was increased. But by using nano extract, in addition to maintaining high efficiency, the amount of inhibitor was reduced significantly. The highest IE% is 94% at the best dose of nano extract (75 ppm), but the highest IE% is 89% at the best dose of the bulk extract (200 ppm) in H2SO4 solution. Also, for the HCl solution, the highest IE% is 88% at the best dose of nano extract (100 ppm), but the highest IE% is 90% at the best dose of the bulk extract (400 ppm), by polarization method. The PP results suggest that this compound has an effect on both anodic, and cathodic processes, and that it adsorbs on mild steel surface according to the Langmuir adsorption isotherm. Optical microscopy, scanning electron microscopy (SEM) analysis, and a solid UV-Visible reflection spectrum were used to investigate the alloys' surface morphology.

SnO2@ZnO nanocomposites doped polyaniline polymer for high performance of HTM-free perovskite solar cells and carbon-based.

Herein, at first, green SnO2@ZnO nanocomposites were synthesized using Calotropis plant extract as an electron transfer material (ETM) to fabricate low-temperature-processed perovskite solar cells (PSCs). Then, the polyaniline (PANI) polymer was applied as an efficient additive to improve perovskite film quality. Under the effects of the small content of PANI additive, the quality of perovskite films is enhanced, which showed higher crystallinity in (110) crystal plane; also, the perovskite grains were found to be enlarged from 342 to 588 nm. The power conversion efficiency (PCE) of the prepared PSCs with SnO2@ZnO.PANI nanocomposites electron transfer layer (ETL) increased by 3.12%, compared with the PCE of SnO2@ZnO nanocomposites. The perovskite devices using SnO2@ZnO.PANI nanocomposites ETL have shown good stability during 480 h of tests. Furthermore, the optimal PSCs were fabricated by the mp-TiO2/SnO2@ZnO.PANI nanocomposites as ETL, which has a power conversion efficiency of 15.45%. We expect that these results will boost the development of low-temperature ETL, which is essential for the commercializing of high-performance, stable, and flexible perovskite solar cells.

Experimental and theoretical investigation of mild steel corrosion control in acidic solution by Ranunculus arvensis and Glycine max extracts as novel green inhibitors.

In the present research, the ability of Ranunculus arvensis (RA) and Glycine max (GM) extracts as green corrosion inhibitors of mild steel (MS) in 1 M HCl was investigated. The inhibiting potential of RA and GM was analysed employing electrochemical impedance spectroscopy (EIS), polarization curves, potentiometry, and theoretical investigations. An enhancement in the inhibition efficiency (I.E) with increasing inhibitors concentrations indicated by EIS data and polarization curves. According to obtained results both extracts indicated inhibitory effect, with their effectiveness following the order of RA > GM. In addition, the interactions between the inhibitors on the MS surface were assessed using B3LYP/6-311g(d,p) theory level in liquid water phase. The interaction energies for three orientations of RA and GM depicted that inhibitors have located parallel to the alloy surface. The preferred complex orientation is one in which the maximum number of inhibitor donor atoms interacted with the alloy surface. Finally, experimental and theoretical results were in accordance which confirmed the inhibition effect of RA and GM extracts.

Metoprolol: New and Efficient Corrosion Inhibitor for Mild Steel in Hydrochloric and Sulfuric Acid Solutions.

The inhibition behavior of metoprolol tablet on steel alloy (st37) in 1 M hydrochloric acid and 0.5 M sulfuric acid solutions were studied by three methods (potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electronic microscopy, SEM). The obtained parameters revealed that different amounts of metoprolol drug inhibited the corrosion of mild steel in the acid solutions of HCl and H2SO4. The corrosion resistance of the alloy increased with the increase in the concentration of metoprolol up to 300 ppm but was reduced by increasing the temperature. The derived parameters from polarization curves indicated that the drug is a mixed type inhibitor. The results obtained from the different methods are consistent with each other. The adsorption of metoprolol was found to be physical, exothermic, and spontaneous, and also fitted the Langmuir adsorption model. SEM micrographs are in accordance with the adsorption performance of the tablet.