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Highlights: [•] Adsorption of medetomidine on graphene was investigated. [•] This study describes powerful method for designating a logical electrochemical mechanism. [•] π-π interactions between the adsorbed molecules and graphene were investigated. [Copyright &y& Elsevier]

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 glucose-capped CdSe quantum dots (QDs) and 1-ethyl-3-methyl-imidazolium:PF 6 (EtMIMPF 6 ) ionic liquid (IL) have been incorporated in the graphite paste electrode (GPE) and used for the voltammetric determination of minoxidil. The high permeability of IL as a hydrophilic binder to polar species, in addition to improving the faradaic current, resulted in increased capacitive current. In order to further improvement of the faradaic signal, we employed a glucose-capped CdSe QDs. Cyclic voltammetry and Faradaic impedance spectroscopy (FIS) indicated that incorporating the QDs into the composite matrix although was not able to significantly improve the kinetics of minoxidil oxidation, but remarkably enhanced the magnitude of the anodic peak current. The sluggish expansion of diffusion layer in viscose IL medium and the microdisc-geometry like behaviour of nanoparticles provided a proper condition for transition from the planar semi-infinite diffusion to the thin layer behaviour. Density functional theory (DFT) was found to yield a good description of the enhancement of signal in the presence of nanomaterials. The results of calculation support that the change in diffusion manner, and not improving in the electron transfer capability at electrode/electrolyte interface, is responsible for the observed signal enhancement. A detailed mechanism for oxidation of minoxidil was also proposed. [ABSTRACT FROM AUTHOR]