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This study aims to synthesize two organic heterocyclic compounds, (2E,3E)-6-chloro-2,3-dihydrazinylidene-1-methyl-1,2,3,4-tetrahydroquinoxaline (MR1) and (2E,3E)-2,3-dihydrazinylidene-1-methyl-1,2,3,4-tetrahydroquinoxaline (MR2), characterize them using nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR) and evaluate their effectiveness as corrosion inhibitors in an acidic environment (15% HCl).

The synthesized compounds, MR1 and MR2, were tested for their corrosion inhibition properties using potentiodynamic polarization and electrochemical impedance spectroscopy. Post-corrosion, the steel surface was analyzed with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) to confirm the adsorption of the compounds. The experimental findings were further supported by density functional theory calculations and molecular dynamics simulations.

The results indicated that both MR1 and MR2 exhibit significant anticorrosive activity in a 15% HCl environment. The analyses performed with SEM, EDX and AFM confirmed the effective adsorption of the inhibitors on the steel surface, forming a protective layer. Theoretical studies provided additional insights into the adsorption mechanisms and stability of the inhibitors.

This work introduces novel organic heterocyclic compounds based on quinoxalinone as effective corrosion inhibitors in acidic environments. The combined experimental and theoretical approach provides a comprehensive understanding of their anticorrosive behavior.

Corrosion is a major concern for many industries that use metals as structural or functional materials, and the use of corrosion inhibitors is a widely accepted strategy to protect metals from deterioration in corrosive environments. Moreover, the toxic nature, non-biodegradability and price of most conventional corrosion inhibitors have encouraged the application of greener and more sustainable options, with natural and synthetic drugs being major actors. Hence, this paper aims to stress the capability of natural and synthetic drugs as manageable and sustainable, environmentally friendly solutions to the problem of metal corrosion.

In this review, the recent developments in the use of natural and synthetic drugs as corrosion inhibitors are explored in detail to highlight the key advancements and drawbacks towards the advantageous utilization of drugs as corrosion inhibitors.

Corrosion is a critical issue in numerous modern applications, and conventional strategies of corrosion inhibition include the use of toxic and environmentally harmful chemicals. As greener alternatives, natural compounds like plant extracts, essential oils and biopolymers, as well as synthetic drugs, are highlighted in this review. In addition, the advantages and disadvantages of these compounds, as well as their effectiveness in preventing corrosion, are discussed in the review.

This survey stresses on the most recent abilities of natural and synthetic drugs as viable and sustainable, environmentally friendly solutions to the problem of metal corrosion, thus expanding the general knowledge of green corrosion inhibitors.

The purpose of this study is to evaluate the corrosion retardation properties of methylene blue on carbon steel in hydrochloric acid solutions.

The corrosion inhibition property of methylene blue on carbon steel was investigated by hydrogen evolution technique (gasometric technique) and weight loss measurements at 303 K and 333 K in hydrochloric acid solutions.

The results revealed that methylene blue inhibited the corrosion carbon steel, and the inhibition efficiency was temperature dependent. The maximum inhibition efficiencies were 88% at 303 K and 79.2% at 333 K. The corrosion data was consistent with the Langmuir adsorption isotherm which posits that the methylene blue molecules adhered to the metal substrate. The corrosion kinetics followed the first-order kinetic reaction equation. The activation energy (Ea) values ranged from 45.6 to 81.7 kJ/mol and indicated physical adsorption.

This paper provides new information on the possible application of methylene blue as corrosion inhibitor for carbon steel.

This study aims to develop eco-friendly corrosion inhibitors for aluminum in acidic media by evaluating the corrosion inhibition properties of corn leaf extract (CLE) using response surface methodology (RSM) and experiments.

The RSM was combined with experiments to evaluate the corrosion inhibition properties of CLE on aluminum in acid media.

The effectiveness of the inhibition increased with increasing inhibitor concentration and time but decreased with increasing temperature. The corrosion inhibition mechanism revealed the corrosion process is spontaneous exothermic physical adsorption. Thermodynamic parameters revealed an activation energy between 32.1 and 24.7 kJ/mol, energy of adsorption between −14.53 and −65.07 and Gibbs free energy of −10.12 kJ/mol which indicated the CLE exothermically spontaneously physisorbed. A model was generated to estimate the effect of the process parameters (inhibitor concentration, reaction time and temperature) using the RSM. Optimization of the process factors was also carried out using the RSM. The percentage inhibition efficiency obtained experimentally (85.61%) was closely comparable to 84.89% obtained by the theoretical technique (RSM). The SEM observations of the inhibited and uninhibited Al samples demonstrated that CLE is an effective corrosion inhibitor for aluminum in acid media.

Results herein provide novel information on the possible application of CLEs as effective eco-friendly corrosion inhibitors.

The aim of this study is to evaluate the corrosion inhibitory properties of three piperazine derivatives – Ethyl 5-(piperazine-1-yl) benzofuran-2-carboxylate (EPBC), 5-[4–(1-tert-butoxyethenyl) piperazin-1-yl]-1-benzofuran-2-carboxamide (BBPC) and Tert-butyl-4–(2-(ethoxycarbonyl)benzofuran-5-yl)-piperazine-1-carboxylate (TBPC) – on Al surfaces in the presence of hydrochloric acid (HCl). The research uses density functional theory (DFT) and molecular dynamics simulations to explore the effectiveness of these derivatives as corrosion inhibitors and to understand their adsorption behavior at the molecular level.

This study uses a computational approach using DFT at various levels (B3LYP/6–31+G(d,p), B3LYP/6–311+G(d,p), WB97XD/DGDZVP) to calculate essential quantum chemical parameters such as energy gap (ΔE), ionization energy (I), absolute electronegativity (χ), electron affinity (E), dipole moment (µ), absolute softness (s), fraction of electron transferred (ΔN) and absolute hardness (η). The Fukui function and local softness indices are used to assess the sites for electrophilic and nucleophilic attacks on the inhibitors. Molecular dynamics simulations are performed to analyze the adsorption behavior of these derivatives on the Al (110) surface using the adsorption locator method. Theoretical methods like DFT provide quantum chemical parameters, explaining inhibitor reactivity, whereas molecular dynamics simulate adsorption behavior on Al (110), both supporting and correlating with experimental inhibition efficiency trends.

This study demonstrates that all three piperazine derivatives exhibit strong adsorption on the Al surface, with high adsorption energies, good solubility and low toxicity, making them effective corrosion inhibitors in acidic environments. Among the three, TBPC showed superior inhibitory performance, particularly in the presence of HCl, due to its optimal electronic properties and stable adsorption on the Al (1 1 0) surface.

This research contributes to the field by combining DFT calculations and molecular dynamic simulations to evaluate the corrosion inhibition potential of piperazine derivatives comprehensively. This work advances the understanding of the adsorption mechanisms of organic inhibitors on metal surfaces and offers a detailed quantum chemical and adsorption behavior analysis.

The purpose of this study is to develop a green corrosion inhibitor (GCI) from the parthenium hysterophorus (PHS) leaf and identifying its efficiency in corrosion inhibition of AZ31 alloy.

GCI from PHS leaf is extracted with the aid of Soxhlet apparatus and analysed through Fourier transform infrared spectroscopy (FTIR) and phytochemical tests to identify the functional groups and chemical compounds present. Inhibition efficiency (IE) of PHS extract is identified through polarization analysis and immersion tests in which concentration of PHS extract (0–300 ppm) and temperature (303–353 K) is varied.

Maximum IE of 84% is exhibited by the prepared PHS extract at a concentration of 250 ppm at 303 K and further addition diminishes IE. The developed GCI is found effective in room temperature (303 K) as it exhibits lower IE when temperature increased. Both physical and chemical absorption mechanisms were identified for PHS extract over AZ31 surface, whereas FTIR and SEM analysis confirms the development of passivation layer.

Development of GCI from the leaf of a weed (PHS) that disturbs the ecosystem and identifying its efficiency in preventing corrosion of AZ31 under saline environment.

The corrosion of cupronickel and copper alloys in marine and chloride environments presents significant challenges in the chemical and petrochemical industries. This paper aims to investigate the corrosion inhibition of cupronickel alloy (Cu-10Ni) in a sodium chloride medium using expired amlodipine as a corrosion inhibitor. The use of this drug in its expired form could reduce the costs of corrosion and help mitigate the accumulation of pharmaceutical waste.

The inhibitory action was evaluated using a weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The effect of temperature on the inhibition performance was also studied.

The results of these experiments demonstrated that the drug amlodipine effectively inhibited the corrosion of cupronickel alloy in chloride solutions. The corrosion rate of cupronickel was found to decrease with increasing inhibitor concentration and to increase with rising temperature. A maximum inhibition efficiency of 91.92 was achieved with an inhibitor concentration of 0.025 g/L at 298 K. Adsorption of the inhibitor followed the Langmuir adsorption isotherm. Polarization studies indicated that the expired drug acted as a mixed inhibitor. SEM and AFM analyses confirmed that the surface morphology of cupronickel specimens was significantly improved in the presence of the inhibitor.

Amlodipine can be conveniently used to mitigate problems with the corrosion of copper alloys in chloride environments.

Amlodipine is evaluated as a novel and effective corrosion inhibitor for cupronickel alloy in neutral chloride environments.

The study aims to develop an inexpensive metal oxide semiconductor gas sensor with high sensitivity, excellent selectivity for a specific gas and rapid response time.

This study synthesized Zn2SnO4 nanostructures using a hydrothermal method with a 1 M concentration of zinc chloride (ZnCl2) as the zinc source and a 0.7 M concentration of tin chloride (SnCl4) as the tin source. Thick films of nanostructured Zn2SnO4 were then produced using screen printing. The structural properties of Zn2SnO4 were confirmed using X-ray diffraction, and the formation of Zn2SnO4 nanoparticles was verified by transmission electron microscopy. Scanning electron microscopy was used to analyse the surface morphology of the fabricated material, while energy dispersive spectroscopy provided insight into the chemical composition of the thick film. These fabricated thick films underwent testing for various hazardous gases, including nitrogen dioxide, ammonia, hydrogen sulphide (H2S), ethanol and methanol.

The nanostructured Zn2SnO4 thick film sensor demonstrates a notable sensitivity to H2S gas at a concentration of 500 ppm when operated at 160°C. Its selectivity, response time and recovery time were assessed and documented.

The primary limitations of this research on metal oxide semiconductor gas sensors include poor selectivity to specific gases, limited durability and challenges in achieving detection at room temperature.

The nanostructured Zn2SnO4 thick film sensor demonstrates a strong response to H2S gas, making it a promising candidate for commercial production. The detection of H2S is crucial in various sectors, including industries and sewage plants, where monitoring this gas is essential.

Currently, heightened global apprehension about atmospheric pollution stems from the existence of perilous toxic and flammable gases. This underscores the imperative need for monitoring such gases. Toxic and flammable gases are frequently encountered in both residential and industrial environments, posing substantial hazards to human health. Noteworthy accidents involving flammable gases have occurred in recent years. It is crucial to comprehend the presence and composition of these gases in the surroundings for precise detection, measurement and control. Thus, there has been a significant push for extensive research and development in diverse sensor technologies using various materials and methodologies to monitor and regulate these gases effectively.

In this research, Zn2SnO4 nanostructures were synthesized using a hydrothermal method with ZnCl2 at a concentration of 1 M for zinc and SnCl4 at a concentration of 0.7 M for tin. Thick films of nanostructured Zn2SnO4 were then fabricated via screen printing technique. Following fabrication, all thick films were subjected to testing with various toxic gases, and the results were compared to previously published data. The analysis indicated that the nanostructured Zn2SnO4 thick film sensor demonstrated outstanding performance concerning gas response, gas concentration, selectivity and response time, particularly towards H2S gas.

This study aims to observe the coloring efficacy of graphite (G) and nano bentonite clay (BCNPs) on the adsorption of Basic Blue 5 dye from residual dye bath solution.

Some factors that affected the adsorption processes were examined and found to have significant impacts on the adsorption capacity such as the initial concentration of G and/or BCNPs (Co: 40–2,320 mg/L), adsorbent bath pH (4–9), shaking time (30–150 min.) and initial dye concentration (40–200 mg/L). The adsorption mechanism of dye by using G and/or BCNPs was studied using two different models (first-pseudo order and second-pseudo order diffusion models). The equilibrium adsorption data for the dye understudy was analyzed by using four different models (Langmuir, Freundlich, Temkin modle and Dubinin–Radushkevich) models.

It has been found that the adsorption kinetics follow rather a pseudo-first-order kinetic model with a determination coefficient (R²) of 0.99117 for G and 0.98665 for BCNPs. The results indicate that the Freundlich model provides the best correlation for G with capacities q_max = 2.33116535 mg/g and R² = 0.99588, while the Langmuir model provides the best correlation for BCNPs with R² = 0.99074. The adsorbent elaborated from BCNPs was found to be efficient and suitable for removing basic dyes rather than G from aqueous solutions due to its availability, good adsorption capability, as well as low-cost preparation.

There is no research limitation for this work. Basic Blue 5 dye graphite (G) and nano bentonite clay (BCNPs) were used.

This work has practical applications for the textile industry. It is concluded that using graphite and nano bentonite clay can be a possible alternative to adsorb residual dye from dye bath solution and can make the process greener.

Socially, it has a good impact on the ecosystem and global community because the residual dye does not contain any carcinogenic materials.

The work is original and contains value-added products for the textile industry and other confederate fields.