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The inhibition effect of a Schiff base with several functional groups on the corrosion of aluminum in alkaline solution is studied by experimental techniques and density function theory (DFT) calculations. The Schiff base are characterized by 1 HNMR, 13 CNMR, FT-IR, and CHN elemental analysis. In addition, different electrochemical and corrosion techniques such as weight loss, tafel polarization, electrochemical impedance spectroscopy (EIS) and optical microscopy images are performed to analyze the inhibiting performances. In the Tafel measurements the cathodic Tafel slopes values incurred small changes with increasing the inhibitor concentration, which revealed that the inhibitor was adsorbed on the aluminum surface. The inhibition efficiencies are calculated from weight loss measurement and electrochemical tests. The adsorption of the inhibitor onto the aluminum surface follows the Langmuir adsorption isotherm with the free adsorption energy of −8.66 kJ mol −1 . The calculated adsorption energies and the amount of charge transfer obtained by DFT calculation revealed that corrosion inhibition effectively occurs with chemisorption, where new N Al bonds are formed between of N atoms in azo (–N N–) group and Al surface atoms, which is confirmed from ab initio molecular dynamics (AIMD) simulation. [ABSTRACT FROM AUTHOR]

The electrochemical performance of Al, Al–0.5 Mg–0.1 Sn–0.03 Ga–0.007 Pb (Alloy 1) and Al–0.5 Mg–0.1 Sn–0.05 Ga–0.07 Pb (Alloy 2) (wt.%) in 2 M NaCl solution has been investigated by using open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy and galvanostatic discharge. The results suggest that the protective oxide layer on the Alloy 2 is unstable and pitting corrosion in weak points is evident while the Al surface is covered with passive layer. The addition of lead and gallium alloying elements to aluminum causes significant activation of aluminum. Gallium and tin as alloying additives in alloy composition can result in the adsorption of Cl − ions in the active sites at more electronegative potentials and therefore activate the alloy. The activation is revealed by shifting the open circuit potential in the negative direction, considerable increasing of corrosion current density and removal of the passive potential region. The extent of activation depends on the amount of the alloying elements and there is an increase in the following order: Al < Alloy 1 < Alloy 2. The galvanostatic discharge tests, combined with the results of impedance and potentiodynamic polarization confirmed the great activity of Alloy 2 compared to Alloy 1 and Al. [ABSTRACT FROM AUTHOR]

As redox‐active based supercapacitors are known as highly desirable next‐generation supercapacitor electrodes, the targeted design of two ferrocene‐functionalized (Fc(COOH)2) clusters based on coinage metals, [(PPh3)2AgO2CFcCO2Ag(PPh3)2]2⋅7 CH3OH (SC1: super capacitor) and [(PPh3)3CuO2CFcCO2Cu(PPh3)3]⋅3 CH3OH (SC2), is reported. Both structures are fully characterized by various techniques. The structures are utilized as energy storage electrode materials, giving 130 F g−1 and 210 F g−1 specific capacitance at 1.5 A g−1 in Na2SO4 electrolyte, respectively. The obtained results show that the presence of CuI instead of AgI improves the supercapacitive performance of the cluster. Further, to improve the conductivity, the PSC2 ([(PPh3)2CuO2CFcCO2]∞), a polymeric structure of SC2, was synthesized and used as an energy storage electrode. PSC2 displays high conductivity and gives 455 F g−1 capacitance at 3 A g−1. The PSC2 as a supercapacitor electrode presents a high power density (2416 W kg−1), high energy density (161 Wh kg−1), and long cycle life over 4000 cycles (93 %). These results could lead to the amplification of high‐performance supercapacitors in new areas to develop real applications and stimulate the use of the targeted design of coordination polymers without hybridization or compositions with additive materials. [ABSTRACT FROM AUTHOR]

Ferrocene and its derivatives, especially ferrocene‐based coordination polymers (Fc‐CPs), offer the benefits of high thermal stability, two stable redox states, fast electron transfer, and excellent charge/discharge efficiency, thus holding great promise for electrochemical applications. Herein, we describe the synthesis and electrochemical applications of Fc‐CPs and reveal how the incorporation of ferrocene units into coordination polymers containing other metals results in unprecedented properties. Moreover, we discuss the usage of Fc‐CPs in supercapacitors, batteries, and sensors as well as further applications of these polymers, for example in electrocatalysts, water purification systems, adsorption/storage systems. [ABSTRACT FROM AUTHOR]

We introduce high-performance polyaniline (PANI) nanocomposite supercapacitors based on gamma aluminum oxide (γ-Al 2 O 3 ) and gamma iron (III) oxide (γ-Fe 2 O 3 ) nanoparticles with a high specific surface area. PANI and its polymer nanocomposites are synthesized via in situ electropolymerization on gold electrodes. The structures and morphologies are characterized by cyclic voltammetry, FT-IR spectroscopy, SEM, TEM, and EDX. The electrochemical properties and specific surface area of the electrodes are investigated by galvanostatic charge–discharge, electrochemical impedance spectroscopy (EIS) and BET theory. The enhanced specific capacitance with higher surface area and conductivities is observed in PANI/γ-Fe 2 O 3 (342 F/g), PANI/γ-Al 2 O 3 (292 F/g) and PANI (180 F/g) electrodes with a constant current density of 1A/g. The cyclic performance of the PANI electrodes following 8000 cycles of operations were at 87% (PANI), 91% (PANI/γ-Al 2 O 3 ), and 93% (PANI/γ-Fe 2 O 3 ) of their initial capacitance. In addition, higher specific capacitances, higher conductivity and cyclic self-stabilities observed for the PANI/nanocomposite electrodes can provide new opportunities in the field of energy storage and supercapacitor applications. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) and polypyrrole-based gamma aluminum oxide (γ-Al 2 O 3 ) and gamma iron (III) oxide (γ-Fe 2 O 3 ) nanocomposites were synthesized via in situ electropolymerization methods Films were characterized via cyclic voltammetry (CV) and in situ spectroelectrochemistry methods such as in situ UV–Visible spectroscopy and in situ conductivity measurements. Polymer nanocomposite structures and morphologies were studied and characterized via Fourier transform infrared (FT-IR) spectroscopy, electrochemical impedance spectroscopy (EIS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the CV results of the nanocomposites, the separation of anodic and cathodic peak potential of the redox couples (ΔE) exhibited good reversibility with a positive potential shift compared with PPy during redox sweeps. The electrochemical properties of PPy, PPy/γ-Fe 2 O 3, and PPy/γ-Al 2 O 3 nanocomposite electrodes in a solution of H 2 SO 4 were studied via CV, galvanostatic charge–discharge, and EIS measurements to understand the pseudocapacitance that formed due to oxidation and reduction reactions over the double layer capacitance. Results for the nanocomposites revealed that they were very good candidates for supercapacitor applications, with higher specific capacitances, cyclic self-stabilities, and better rate capabilities than those of PPy films. The specific capacitance values of PPy/γ-Fe 2 O 3 (106 F/g) and PPy/γ-Al 2 O 3 (92 F/g) nanocomposites based on a three-electrode cell configuration from galvanostatic charge–discharge at a constant current density of 1 A/g were higher than that for PPy (75 F/g). [ABSTRACT FROM AUTHOR]