Metal surfaces can become damaged by corrosion when they interact with their surroundings, leading to huge financial losses. The use of corrosion inhibitors is one of the most crucial ways to combat the risky and hazardous effects of corrosion. In the present research, electrochemical techniques and surface analysis have been used to characterize the inhibition properties of (3-hydroxy-4-((4-nitrophenyl)diazenyl)-5-(phenylamino)thiophen-2-yl)(phenyl)methanone for the corrosion of carbon steel in an aerated 1.0 M HCl solution. Steel’s corrosion resistance was discovered to be improved by the presence of the examined inhibitor in 1.0 M HCl medium through the adsorption of the inhibitor species to create a barrier layer. The findings showed that when inhibitor concentrations increased and solution temperatures decreased, the inhibition performance (%IE) of the compound under study enhanced. In the light of inhibitor probe’s chemical makeup and theoretical analysis, the mechanism of the inhibition process was addressed. In a 1.0 M HCl solution containing 5 × 10⁻⁵ M of the inhibitor, the inhibition performance, at room temperature, was found to be almost 97%. The electrochemical results revealed that the examined compound successfully prevented carbon steel corrosion as a mixed-type inhibitor. The Langmuir and Freundlich isotherms are pursued by the adsorption of the examined inhibitor. Additionally, using Arrhenius and transition state equations, the activation thermodynamic parameters ΔE_a, ΔH*, and ΔS* were determined and explained. The adsorption process was illustrated using DFT computation and MC simulations. The experimental findings and theoretical simulations concurred surprisingly well. Finally, the paper presents a discussion of the inhibitory mechanism.

In this report, N-benzylhydrazinecarbothioamide (BHCTA) was investigated as an organic inhibitor for the corrosion of copper substrate in 3.5 wt.% sodium chloride electrolyte at 298 K. The inhibition efficiency of BHCTA was examined using electrochemical, chemical and theoretical tools. The gained outcomes indicated a supreme inhibition efficiency of BHCTA which exceeded 95 % upon addition of 1.00 mM of BHCTA. Such supreme efficiency was discussed on the basis of decisive adsorption of BHCTA molecules on the copper substrate that hinders concurrently the anodic oxidation and cathodic reduction reactions progressions. The adsorption of BHCTA on the copper surface was discovered to obey Langmuir isotherm. The resulting value of DGads0 = −35.7 kJ mol−1 indicates that BHCTA molecules adsorb on the copper surface through a spontaneous mix of physisorption and chemisorption processes. A scanning electron microscope was used to examine the effect of BHCTA adsorption on the morphology of the copper surface. Theoretical calculations showed that BHCTA has good adsorption properties on Cu substrate. There is a good consistency between the applied experimental and theoretical tools, confirming the validity of the gained outcomes.

Sulfur mustard (SM) is a harmful warfare agent that poses a serious threat to human health and the environment. Thus, the design of porous materials capable of sensing and/or capturing SM is of utmost importance. In this paper, the interactions of SM and its derivatives with ethylpillar[5]arene (EtP[5]) and the interactions between SM and a variety of host macrocycles were investigated through molecular docking calculations and non-covalent interaction (NCI) analysis. The electronic quantum parameters were computed to assess the chemical sensing properties of the studied hosts toward SM. It was found that dispersion interactions contributed significantly to the overall complexation energy, leading to the stabilization of the investigated systems. DFT energy computations showed that SM was more efficiently complexed with DCMP[5] than the other hosts studied here. Furthermore, the studied macrocyclic containers could be used as host-based chemical sensors or receptors for SM. These findings could motivate experimenters to design efficient sensing and capturing materials for the detection of SM and its derivatives.

The reuse of expired drugs has become a challenge to maintain environmental clean-liness and achieve economic benefit. In this report, two expired drugs, moxifloxacin and norfloxacin, were used as inhibitors for copper corrosion in 3.5 % NaCl solution at different temperatures using several experimental approaches including chemical, electrochemical and spectroscopic techniques. The interaction of these two molecules on the copper surface was also inspected using different adsorption models. Using a dose of 500 mg L-1 of these drugs at 298 K, maximum inhibition efficiencies (IE) of 88.7 and 85.2 % were estimated from the potentiodynamic polarization technique for Mox and Nor, respectively., confirming that they can be considered as promising and effective inhibitors. The IE values were enhanced with increasing drugs doses and reduced with rising temperature. The higher IE is due to the strong adsorption of these molecules on the copper surface and such adsorption is physical in nature and follows the Langmuir adsorption isotherm. This is due to their unique chemical structures as they contain a number of functional groups. Polarization experiments confirmed that the drugs were tuned to behave as mixed-type inhibitors with an anodic predominance. All thermos¬dynamic and kinetic parameters were calculated and discussed in details, and the inhibition mechanism is proposed. All experimental results obtained by different techniques were in agreement with each other.