Alamiery Ahmed A
Al-Ayen Scientific Research Center, Al-Ayen Iraqi University (AUIQ), P.O. Box 64004, An Nasiriyah, Thi Qar, Iraq.
Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Malaysia.
Sci Rep. 2025 Mar 26;15(1):10349. doi: 10.1038/s41598-025-95104-9.
The corrosion inhibition performance of 5-imino-1,2,4-dithiazolidine-3-thione (IDTT) on mild steel in 1.0 M HCl solution was comprehensively evaluated using weight loss measurements, electrochemical techniques, adsorption studies, and density functional theory (DFT) calculations. This study uniquely integrates experimental and theoretical approaches to provide a comprehensive understanding of IDTT's adsorption behavior and inhibition mechanism. Weight loss measurements demonstrated a significant reduction in corrosion rate (CR) from 5.74 mg·cm·h⁻ (blank) to 0.31 mg·cm·h at 0.5 mM, achieving a maximum inhibition efficiency (IE%) of 84.3%. Potentiodynamic polarization studies confirmed that IDTT functions as a mixed-type inhibitor, effectively suppressing both anodic and cathodic reactions. The corrosion current density (i) decreased from 9.9 to 2.7 µA·cm at 303 K, while polarization resistance (Rp) increased from 50.3 Ω (blank) to 149.2 Ω at 0.5 mM, indicating enhanced surface protection. Adsorption studies revealed that IDTT follows the Langmuir adsorption isotherm, suggesting monolayer adsorption with an adsorption equilibrium constant (K) of 1.32 × 10 M. The calculated Gibbs free energy of adsorption (ΔG = -19.83 kJ·mol) indicates that physisorption dominates the adsorption mechanism, ensuring effective surface coverage. DFT calculations provided molecular-level insights into IDTT's inhibition mechanism, revealing a HOMO energy of -8.458 eV and a LUMO energy of 1.2 eV, which confirm strong electronic interactions with the metal surface. Mulliken charge analysis identified sulfur and nitrogen atoms as active adsorption sites, reinforcing IDTT's ability to form a stable protective layer on mild steel. This study demonstrates the novelty of IDTT as a highly efficient corrosion inhibitor, combining experimental validation and computational analysis to establish its adsorption mechanism and surface interactions. The findings highlight IDTT's potential for industrial applications as a sustainable and effective inhibitor for corrosion control in acidic environments.
采用失重测量法、电化学技术、吸附研究和密度泛函理论（DFT）计算，全面评估了5-亚氨基-1,2,4-二噻唑烷-3-硫酮（IDTT）在1.0 M HCl溶液中对低碳钢的缓蚀性能。本研究独特地整合了实验和理论方法，以全面了解IDTT的吸附行为和缓蚀机理。失重测量表明，在0.5 mM时，腐蚀速率（CR）从5.74 mg·cm·h⁻（空白）显著降低至0.31 mg·cm·h，最大缓蚀效率（IE%）达到84.3%。动电位极化研究证实，IDTT作为混合型缓蚀剂，能有效抑制阳极和阴极反应。在303 K时，腐蚀电流密度（i）从9.9降至2.7 μA·cm，而极化电阻（Rp）在0.5 mM时从50.3 Ω（空白）增加到149.2 Ω，表明表面保护增强。吸附研究表明，IDTT遵循朗缪尔吸附等温线，表明为单层吸附，吸附平衡常数（K）为1.32×10 M。计算得到的吸附吉布斯自由能（ΔG = -19.83 kJ·mol）表明，物理吸附主导吸附机理，确保有效的表面覆盖。DFT计算提供了IDTT缓蚀机理的分子水平见解，揭示了最高占据分子轨道（HOMO）能量为-8.458 eV，最低未占据分子轨道（LUMO）能量为1.2 eV，这证实了与金属表面的强电子相互作用。Mulliken电荷分析确定硫和氮原子为活性吸附位点，增强了IDTT在低碳钢上形成稳定保护层的能力。本研究证明了IDTT作为一种高效缓蚀剂的新颖性，结合实验验证和计算分析，确定了其吸附机理和表面相互作用。研究结果突出了IDTT作为酸性环境中腐蚀控制的可持续有效缓蚀剂在工业应用中的潜力。
