In the present work, we present the superior corrosion inhibition properties of three plant-based products, Fraxinus excelsior (FEAE), Zingiber zerumbet (ZZAE), and Isatis tinctoria (ITAE), that efficiently inhibit the corrosion of mild steel in phosphoric acid. The anti-corrosion and adsorption characteristics were assessed using a combination of experimental and computational approaches. Weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy methods were used to evaluate the inhibitive performance of the inhibitors on the metal surface. Then, both DFT/DFTB calculations and molecular dynamic simulations were further adopted to investigate the interaction between organic inhibitor molecules and the metal surface. The protective layers assembled using the active constituents, such as carbonyl and hydroxyl groups, of the three plant-based products offer high electrochemical stability at high temperatures and robust protection against aggressive acidic solutions. All electrochemical measurements showed that the inhibition performance of extracts increased by increasing their concentration and improved in the following order: FEAE > ZZAE > ITAE. Further, these extracts worked as mixed-type inhibitors to block the anodic and cathodic active sites on the mild steel surface. Multi-level computational approaches revealed that FEAE is the most adsorbed inhibitor owing to its ability to provide electron lone pairs for electrophilic reactions. The experimental and theoretical results showed good agreement. These results indicate the possibility of replacing conventional compounds with natural substituted organic products in the fabrication of hybrid materials with effective anti-corrosion performance.

The growing interest in eco-friendly alternatives has sparked research into essential oils as corrosion inhibitors, offering an innovative approach. Investigating their unique properties, researchers aim to advance corrosion engineering for a sustainable future. Despite promising lab results, the exact mechanism of their action in corrosion engineering is not fully understood, highlighting the need for further exploration. Using computational modeling, we explored how grape seed oil (GSO) compounds interact with carbon steel (C38) surfaces, unraveling the inhibitive properties against corrosion. Employing various simulation methods, such as density functional theory (DFT), density functional-based tight-binding (DFTB), and molecular dynamics (MD), this study validates experimental findings and unveils novel insights into the underlying mechanisms of these interactions. Quantitative analysis quantifies the inter- and intramolecular synergistic effect and suggests that the LA@OA promotes the charge-transfer process. DFTB calculations reveal that the synergistic action in the parallel adsorption configuration of LA and OA molecules is sufficiently strong to form a stable adsorption layer on the Fe surface with a large negative value of E_ads (6.74 eV). Experimental results demonstrated that the inhibition performance of GSO extract exhibited a notable increase with increasing concentrations, reaching a higher efficiency of 79% at 0.5 g/L of GSO. EIS results demonstrated that the existence of the GSO inhibitor film increases the resistance of the charge transfer (about 80 Ω cm² at 0.5 g/L), indicating the superior barrier anticorrosion properties of the formed film. The theoretical results validate the exceptional anticorrosion performance and provide compelling evidence of the remarkable ability to prevent corrosion of C38 substrate. The findings offer potential pathways for the development of eco-friendly alternatives and interestingly provide a foundation understanding in the field.

This study examines the environmental challenges posed by azo-dye pollutants and aluminum industrial waste. Aluminum oxide nanoparticles (P/Al₂O₃-NPs) were produced using a green method that utilized pharmaceutical packaging waste as an aluminum source and marine algae extract (Padina pavonica) as reducing and stabilizing agents and that was characterized by XRD, EDX, SEM, TEM, and zeta potential. Batch biosorption studies were performed to assess the effectiveness of P/Al₂O₃-NPs in removing CR dye from aqueous solutions. The results demonstrate that the particle sizes range from 58.63 to 86.70 nm and morphologies vary from spherical to elliptical. FTIR analysis revealed Al–O lattice vibrations at 988 and 570 cm⁻¹. The nanoparticles displayed a negative surface charge (−13 mV) and a pH_zpc of 4.8. Adsorption experiments optimized parameters for CR dye removal, achieving 97.81% efficiency under native pH (6.95), with a dye concentration of 30 mg/L, an adsorbent dosage of 0.1 g/L, and a contact time of 30 min. Thermodynamic studies confirmed that the process is exothermic and spontaneous. Kinetic data fit well with the pseudo-second-order model, while equilibrium data aligned with the Langmuir isotherm. The adsorption mechanism involved van der Waals forces, hydrogen bonding, and π–π interactions, as supported by the influence of pH, isotherm data, and FTIR spectra. Overall, the study demonstrates the potential of eco-friendly P/Al₂O₃-NPs to efficiently remove CR dye from aqueous solutions.

Fabrication of magnetic materials via a facile and environmentally favorable process with high self-heating performance is quite favored for biomedical applications. To tackle this challenge, magnetic ferrite nanoparticles were developed through an ultrasonic-assisted coprecipitation process. Magnetite (Fe₃O₄), magnetite doped with cobalt nanoparticles (Co_0.4Fe_2.6O₄), and magnetite doped with cobalt/zinc nanoparticles (Zn_0.15Co_0.25Fe_2.6O₄) were synthesized using ultrasonic-assisted coprecipitation techniques. Specific loss power (SLP) was estimated to optimize the heating influence under varied magnetic fields, coating agents, and dispersing solvents. Magnetite doped with cobalt/zinc nanoparticles demonstrated elevated SLP 110 W/g with preferable hyperthermic performance, where AMF conditions did not surpass the safety border for human exposure. The self-heating performance of magnetite doped with cobalt/zinc nanoparticles increased with increasing strength at a constant frequency. The self-heating performance of magnetite nanoparticles increased with increasing frequency at constant strength. Hence, the prepared magnetite doped with cobalt/zinc nanoparticles by the ultrasonic-assisted coprecipitation process can be appropriate for biomedical applications.