Design of New Ecofriendly Schiff Base Inhibitors for Carbon Steel Corrosion Protection in Acidic Solutions: Electrochemical, Surface, and Theoretical Studies.

Corrosion poses a significant problem for several industrial sectors, inducing continuous research and development of corrosion inhibitors for use across a wide range of industrial applications. Here, we report the effectiveness of three newly developed Schiff bases derived from amino acids and 4-aminoacetophenone, namely, AIP, AMB, and AImP, as environmentally friendly corrosion inhibitors for Q235 steel in hydrochloric acid using electrochemical and surface analyses, in addition to theoretical techniques. The electrochemical findings of potentiodynamic polarization (PDP) demonstrated that the explored compounds serve as mixed-type inhibitors and can effectively suppress steel corrosion, with maximal protection efficiencies of 93.15, 96.01, and 77.03% in the presence of AIP, AMB, and AImP, respectively, at a concentration of 10 mM. The electrochemical impedance spectroscopy (EIS) and polarization results confirmed the growth of a durable protective barrier on the steel surface in the existence of the inhibitors, which is responsible for decreasing the metallic dissolution. Results were further supported by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV-vis, and Fourier transform infrared (FTIR), which ascribed the development of inhibitor-adsorption films on the steel surface. The results of EDS and XPS analyses demonstrated the existence of the distinctive elements of the inhibitors on the metallic surface. Furthermore, density functional theory (DFT) calculations and Monte Carlo (MC) simulations showed the electronic structure of the examined inhibitors and their optimized adsorption configurations on the steel surface, which helped in explaining the anticorrosion mechanism. Finally, the theoretical and experimental findings exhibit a high degree of consistency.

Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems.

In this study we present a novel energy transfer material inspired by natural light-harvesting antenna arrays, zinc(II) phthalocyanine-pyrene (ZnPcPy). The ZnPcPy system facilitates energy transfer from 16 covalently linked pyrene (Py) donor chromophores to the emissive central zinc(II) phthalocyanine (ZnPc) core. Nearly 98% energy transfer efficiency is determined from the changes in emission decay rates between free MePy to covalently linked Py, supported by comparisons of photoluminescence quantum yields using different excitation wavelengths. A comparative analysis of ZnPcPy and an equivalent mixture of ZnPc and MePy demonstrates the superior light-harvesting performance of the covalently linked system, with energy transfer rates 9705 times higher in the covalently bound system. This covalent strategy allows for very high loadings of absorbing Py chromophores to be achieved while also avoiding exciton quenching that would otherwise arise, with the same strategy widely applicable to other pairs of Forster resonance energy transfer (FRET) chromophores.

Enhancement of Supercapacitor Performance of Electrochemically Grown Nickel Oxide by Graphene Oxide.

ß-Ni(OH)2 and ß-Ni(OH)2/graphene oxide (GO) were prepared on an Ni foil electrode using the electrochemical cyclic voltammetry formed in 0.5 M KOH solution. Several surface analyses such as XPS, XRD, and Raman spectroscopies were used to confirm the chemical structure of the prepared materials. The morphologies were determined using SEM and AFM. The addition of the graphene oxide layer showed a remarkable increase in the specific capacitance of the hybrid. Through the measurements, the specific capacitance values were 280 F g-1 and 110 F g-1 after and before adding 4 layers of GO, respectively. The supercapacitor displays high stability until 500 cycles are charged and discharged almost without a loss in its capacitance values.

Development of Uniform Porous Carbons From Polycarbazole Phthalonitriles as Durable CO2 Adsorbent and Supercapacitor Electrodes.

Advances in new porous materials have recognized great consideration in CO2 capture and electrochemical energy storage (EES) applications. In this study, we reported a synthesis of two nitrogen-enriched KOH-activated porous carbons prepared from polycarbazole phthalonitrile networks through direct pyrolysis protocol. The highest specific surface area of the carbon material prepared by pyrolysis of p-4CzPN polymer reaches 1,279 m2 g-1. Due to the highly rigid and reticular structure of the precursor, the obtained c-4CzPN-KOH carbon material exhibits high surface area, uniform porosity, and shows excellent CO2 capture performance of 19.5 wt% at 0°C. Moreover, the attained porous carbon c-4CzPN-KOH showed high energy storage capacities of up to 451 F g-1 in aqueous electrolytes containing 6.0 M KOH at a current density of 1 A g-1. The prepared carbon material also exhibits excellent charge/discharge cycle stability and retains 95.9% capacity after 2000 cycles, indicating promising electrode materials for supercapacitors.

Effectiveness of Some Novel Ionic Liquids on Mild Steel Corrosion Protection in Acidic Environment: Experimental and Theoretical Inspections.

Three ionic liquids (ILs)-1-butyl-1-methyl-pyrrolidinium Imidazolate (BMPyrIM), 1-butyl-3-methyl-imidazolium Imidazolate (BMImIM), and bis(1-butyl-3-methyl-imidazolium Imidazolate) (BBMImIM)-were synthesized and examined experimentally and theoretically as potential inhibitors for mild steel corrosion in HCl (1.0 M) solution. To our knowledge, two of the ILs successfully synthesized in our laboratory named BMPyrIM and BBMImIM are novel. Different electrochemical (potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS)), surface and structural (scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR)) and theoretical (Density functional theory (DFT)) techniques were utilized to confirm their use as efficient environmentally safe inhibitors. These ionic liquids were designed to study the cation effect (imidazolium and pyrrolidinium) and the dimeric effect of the imidazolium-based IL. A pronounced inhibiting effect was recorded using the optimum concentration (5 × 10-3 M) of BBMImIM with protection efficiency of 98.6% compared to 94.3% and 92.4% for BMImIM and BMPyrIM, respectively. The investigated ILs act as a mixed-type corrosion inhibitors and their protection obeys Langmuir adsorption isotherm. The results obtained by SEM, EDS and AFM confirmed the mild steel protection by the formation of protective film of the ILs on the steel surface resulted in less damaged surfaces compared with the blank solution. Furthermore, quantum chemical calculations illustrated the electronic structure of the investigated ILs and their optimized adsorptiοn configurations on mild steel surface. The findings from the different techniques helped to provide a supported interpretation of the inhibition mechanism.

Electrochemical capacitive performance of thermally evaporated Al-doped CuI thin films.

In this paper, we studied the electrochemical capacitive performance of thermally evaporated copper iodide thin film doped with different quantities of Al (3, 5, 7, and 9 mol%). The morphological structure, crystalline nature, and surface composition of the deposited films with different dopant levels were confirmed using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FE-SEM). The electrochemical performance was evaluated based on cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS) in a Na2SO4 electrolyte. The XRD results confirm that the film is crystalline and has a face-centered cubic structure. The SEM images revealed trihedral-tipped structures with irregular nanocubes. The presence of the trihedral-tipped structures is more obvious in the Al-doped CuI films than in the bare film. We report a progressive increase in the specific capacitance values as the aluminum content increases, from 91.5 F g-1 for the pure CuI film to 108.3, 126.2, 142.8, and 131.1 F g-1 for the films with aluminum content of 3, 5, 7, and 9 mol%, respectively at a scan rate of 2 mV s-1. The optimized CuI-Al electrode with 7 mol% aluminum content showed remarkable long-term cycling stability with 89.1% capacitance retention after 2000 charge/discharge cycles. Such a high performance for the CuI-7Al film as a supercapacitor can be ascribed to the aluminum doping, which increases the electrochemically active area compared to the bare CuI film and is critical for electron exchange at the electrode/electrolyte interface. Therefore, we introduce CuI-Al as a viable option for supercapacitor applications because of its low-cost production, excellent electrochemical performance, and cycling stability.