Pub Date : 2025-10-14DOI: 10.1016/j.ijoes.2025.101210
Abdul Samad Ridha Rashid , Shahin Khameneh Asl , Hamed Asgharzadeh , Taher Rabizadeh , Adel K. Mahmoud
This study introduces a green corrosion inhibitor derived from white bean (Phaseolus vulgaris L.) extract (PVL), an abundant agricultural source, for X42 carbon steel in a CO₂-saturated 3.5 wt% NaCl solution. The anticorrosion performance of the synthesized PVL-extract was evaluated over a concentration range of 50–1000 ppm using weight loss, electrochemical polarization, and impedance spectroscopy (EIS). According to the results, the optimal concentration was 500 ppm, which reduced the corrosion rate by 95.9 ± 8.8 % (from 34.0 ± 2.0 mpy to 1.4 ± 0.3 mpy) and the corrosion current density by 94 ± 1 % (from 12.1 ± 0.2 µA/cm² to 0.7 ± 0.09 µA/cm²), while increasing charge transfer resistance by 88.8 ± 3.6 % (from 330 ± 5 Ω·cm² to 623 ± 7 Ω·cm²). Considering various adsorption isotherms, it was determined that the adsorption of PVL-extract on the carbon steel substrate obeyed the Langmuir adsorption isotherm. AFM provided quantitative surface analysis, revealing a dramatic reduction in average roughness (Sa) from 78 nm (Ra = 285 nm) on the blank coupon to just 0.86 nm (Ra = 5.6 nm) on the sample protected by 500 ppm PVL-extract. This profound smoothing effect was also visually confirmed by SEM. FTIR spectroscopy confirmed the adsorption of the tested inhibitor on the surface of the tested coupons, and UV-Vis spectroscopy verified the formation of inhibitor-iron complexes.
{"title":"Investigation of the corrosion inhibition of X42 carbon steel in CO₂-saturated brine using phaseolus vulgaris L. Bean extract","authors":"Abdul Samad Ridha Rashid , Shahin Khameneh Asl , Hamed Asgharzadeh , Taher Rabizadeh , Adel K. Mahmoud","doi":"10.1016/j.ijoes.2025.101210","DOIUrl":"10.1016/j.ijoes.2025.101210","url":null,"abstract":"<div><div>This study introduces a green corrosion inhibitor derived from white bean (Phaseolus vulgaris L.) extract (PVL), an abundant agricultural source, for X42 carbon steel in a CO₂-saturated 3.5 wt% NaCl solution. The anticorrosion performance of the synthesized PVL-extract was evaluated over a concentration range of 50–1000 ppm using weight loss, electrochemical polarization, and impedance spectroscopy (EIS). According to the results, the optimal concentration was 500 ppm, which reduced the corrosion rate by 95.9 ± 8.8 % (from 34.0 ± 2.0 mpy to 1.4 ± 0.3 mpy) and the corrosion current density by 94 ± 1 % (from 12.1 ± 0.2 µA/cm² to 0.7 ± 0.09 µA/cm²), while increasing charge transfer resistance by 88.8 ± 3.6 % (from 330 ± 5 Ω·cm² to 623 ± 7 Ω·cm²). Considering various adsorption isotherms, it was determined that the adsorption of PVL-extract on the carbon steel substrate obeyed the Langmuir adsorption isotherm. AFM provided quantitative surface analysis, revealing a dramatic reduction in average roughness (Sa) from 78 nm (<em>Ra</em> = 285 nm) on the blank coupon to just 0.86 nm (<em>Ra</em> = 5.6 nm) on the sample protected by 500 ppm PVL-extract. This profound smoothing effect was also visually confirmed by SEM. FTIR spectroscopy confirmed the adsorption of the tested inhibitor on the surface of the tested coupons, and UV-Vis spectroscopy verified the formation of inhibitor-iron complexes.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101210"},"PeriodicalIF":2.4,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-13DOI: 10.1016/j.ijoes.2025.101207
Kai Ren , Jie Zhang , Yangyang Liu , Qingle Hou , Ruiyong Zhang , Mathivanan Krishnamurthy , Zeyu Zuo , Yunyan Zhao , Zhenhua Yu
Protective organic coatings are essential for extending the service life and ensuring the safe, low-carbon operation of industrial circulating-cooling-water heat exchangers. Yet prolonged exposure to high-temperature recirculating water accelerates coating degradation and substrate corrosion, while the underlying galvanic mechanisms remain insufficiently understood. Here, we elucidate these mechanisms by immersing epoxy-coated 20# carbon steel in 40 °C cooling water for 40 days, focusing on localized coating damage with an anode-area ratio of 1:2 (small vs. large anode). During immersion, the coating thickness declined to 96.04 µm and 93.12 µm for the small-anode and large-anode specimens, respectively, while blister density surged by day 20–5.1 n cm−2 and 5.3 n cm−2. Substrate corrosion rates reached 1.143 mm a−1 (small anode) and 1.048 mm a−1 (large anode). The small anode exhibited a markedly stronger “small-anode effect,” generating higher galvanic current density, deeper pits, and more severe localized attack. Corrosion followed a dynamic “film formation-breakdown-reformation” cycle in which iron-based products such as Fe2O3, β-FeOOH, and Fe(OH)3 initially accelerated anodic dissolution, subsequently compacted to form a temporary barrier, and ultimately underwent delamination. By revealing how localized coating failure and galvanic coupling synergistically intensify corrosion and by clarifying the transient protective role of corrosion products, this study advances the fundamental understanding of galvanic corrosion kinetics and provides a mechanistic framework for designing next-generation coatings and predictive-maintenance strategies, thereby driving progress in corrosion science and engineering.
保护性有机涂层对于延长工业循环水热交换器的使用寿命和确保其安全、低碳运行至关重要。然而，长期暴露在高温循环水中会加速涂层降解和基材腐蚀，而潜在的电机制仍未得到充分了解。在这里，我们通过将涂有环氧树脂的20#碳钢浸泡在40°C的冷却水中40天来阐明这些机制，重点研究阳极面积比为1:2（小阳极与大阳极）的局部涂层损伤。浸泡过程中，小阳极和大阳极试样的涂层厚度分别下降到96.04 µm和93.12 µm，而水泡密度在20-5.1 n cm−2和5.3 n cm−2之间急剧增加。腐蚀速率分别为1.143 mm a−1（小阳极）和1.048 mm a−1（大阳极）。小阳极表现出明显更强的“小阳极效应”，产生更高的电流密度、更深的凹坑和更严重的局部攻击。在腐蚀过程中，铁基产物如Fe2O3、β-FeOOH和Fe(OH)3最初加速阳极溶解，随后压实形成临时屏障，最终发生分层。通过揭示局部涂层失效和电偶耦合如何协同加剧腐蚀，阐明腐蚀产物的瞬态保护作用，本研究推进了对电偶腐蚀动力学的基本理解，并为设计下一代涂层和预测性维护策略提供了机制框架，从而推动了腐蚀科学和工程的进步。
{"title":"Failure mechanisms and corrosion behavior of epoxy-based protective coatings prepared on 20# steel exposed to cooling water","authors":"Kai Ren , Jie Zhang , Yangyang Liu , Qingle Hou , Ruiyong Zhang , Mathivanan Krishnamurthy , Zeyu Zuo , Yunyan Zhao , Zhenhua Yu","doi":"10.1016/j.ijoes.2025.101207","DOIUrl":"10.1016/j.ijoes.2025.101207","url":null,"abstract":"<div><div>Protective organic coatings are essential for extending the service life and ensuring the safe, low-carbon operation of industrial circulating-cooling-water heat exchangers. Yet prolonged exposure to high-temperature recirculating water accelerates coating degradation and substrate corrosion, while the underlying galvanic mechanisms remain insufficiently understood. Here, we elucidate these mechanisms by immersing epoxy-coated 20# carbon steel in 40 °C cooling water for 40 days, focusing on localized coating damage with an anode-area ratio of 1:2 (small vs. large anode). During immersion, the coating thickness declined to 96.04 µm and 93.12 µm for the small-anode and large-anode specimens, respectively, while blister density surged by day 20–5.1 n cm<sup>−2</sup> and 5.3 n cm<sup>−2</sup>. Substrate corrosion rates reached 1.143 mm a<sup>−1</sup> (small anode) and 1.048 mm a<sup>−1</sup> (large anode). The small anode exhibited a markedly stronger “small-anode effect,” generating higher galvanic current density, deeper pits, and more severe localized attack. Corrosion followed a dynamic “film formation-breakdown-reformation” cycle in which iron-based products such as Fe<sub>2</sub>O<sub>3</sub>, β-FeOOH, and Fe(OH)<sub>3</sub> initially accelerated anodic dissolution, subsequently compacted to form a temporary barrier, and ultimately underwent delamination. By revealing how localized coating failure and galvanic coupling synergistically intensify corrosion and by clarifying the transient protective role of corrosion products, this study advances the fundamental understanding of galvanic corrosion kinetics and provides a mechanistic framework for designing next-generation coatings and predictive-maintenance strategies, thereby driving progress in corrosion science and engineering.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101207"},"PeriodicalIF":2.4,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-12DOI: 10.1016/j.ijoes.2025.101206
Dongxu Chang , Lin Li , Qianxu Zhang , Hongyang Shen , Xue Han , Anruo Chen , Shengping Wang
The corrosion of aluminum radiators in high-voltage direct current transmission systems severely affects the working state of the converter valve. The inhibition of aluminum corrosion in sodium benzoate (SB) solutions was investigated via potentiodynamic polarization and electrochemical impedance spectroscopy, and the optimal concentration for maximum efficiency was determined. To improve the inhibition performance, −CH3, −NH2, and −NO2 groups were introduced at the para-position to systematically evaluate the inhibition effects of para-substituted derivatives, including para-methyl (PMSB), para-amino (PASB), and para-nitro (PNSB) sodium benzoate. The surface was characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, and theoretical calculations were performed to analyze the molecular orbital distribution, HOMOLUMO energy gaps, Fukui functions, and adsorption energies. The adsorption mechanism and corrosion inhibition mechanism of corrosion inhibitor molecules were identified, and the corrosion inhibition performance from high to low is as follows: PNSB (74.68 %), PASB (72.72 %), PMSB (68.90 %), and SB (64.59 %). PNSB has the best adsorption capacity and corrosion inhibition performance, which is attributed to the electron-withdrawing effect of the −NO2 group, enhancing binding with the aluminum surface and reducing aluminum dissolution.
{"title":"Effects of para-substituted sodium benzoate derivatives on aluminum corrosion inhibition","authors":"Dongxu Chang , Lin Li , Qianxu Zhang , Hongyang Shen , Xue Han , Anruo Chen , Shengping Wang","doi":"10.1016/j.ijoes.2025.101206","DOIUrl":"10.1016/j.ijoes.2025.101206","url":null,"abstract":"<div><div>The corrosion of aluminum radiators in high-voltage direct current transmission systems severely affects the working state of the converter valve. The inhibition of aluminum corrosion in sodium benzoate (SB) solutions was investigated via potentiodynamic polarization and electrochemical impedance spectroscopy, and the optimal concentration for maximum efficiency was determined. To improve the inhibition performance, −CH<sub>3</sub>, −NH<sub>2</sub>, and −NO<sub>2</sub> groups were introduced at the para-position to systematically evaluate the inhibition effects of para-substituted derivatives, including para-methyl (PMSB), para-amino (PASB), and para-nitro (PNSB) sodium benzoate. The surface was characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, and theoretical calculations were performed to analyze the molecular orbital distribution, HOMO<img>LUMO energy gaps, Fukui functions, and adsorption energies. The adsorption mechanism and corrosion inhibition mechanism of corrosion inhibitor molecules were identified, and the corrosion inhibition performance from high to low is as follows: PNSB (74.68 %), PASB (72.72 %), PMSB (68.90 %), and SB (64.59 %). PNSB has the best adsorption capacity and corrosion inhibition performance, which is attributed to the electron-withdrawing effect of the −NO<sub>2</sub> group, enhancing binding with the aluminum surface and reducing aluminum dissolution.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101206"},"PeriodicalIF":2.4,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review highlights the recent advancements of electrochemical nanobiosensors for low-cost clinical diagnosis and POC testing, as well as their potential obstacles and future directions These sensors offer a promising route towards low-cost point-of-care (POC) diagnostics by combining nanomaterials with electrochemical transduction principles to make clinical diagnosis more accessible and user-friendly, particularly in resource-limited settings. Their performance characteristics of high specificity, sensitivity, miniaturization, and ease of use make them excellent for the detection of a wide range of target analytes, including biomarkers for infectious diseases, cancer, and metabolic disorders. This review examines the different types of electrochemical nanobiosensors, their potential applications in low-cost clinical diagnosis, current challenges, and possible prospects. To solve the remaining issues and realize the full capacity of these technologies to improve healthcare access and affordability on a global level, we point out the importance of further research and development.
{"title":"Electrochemical nanobiosensors for low-cost clinical diagnosis","authors":"Bambang Kuswandi , Rizanty Amalia , Dian Ayu Eka Pitaloka , Bayu Tri Murti , Mochammad Amrun Hidayat","doi":"10.1016/j.ijoes.2025.101205","DOIUrl":"10.1016/j.ijoes.2025.101205","url":null,"abstract":"<div><div>This review highlights the recent advancements of electrochemical nanobiosensors for low-cost clinical diagnosis and POC testing, as well as their potential obstacles and future directions These sensors offer a promising route towards low-cost point-of-care (POC) diagnostics by combining nanomaterials with electrochemical transduction principles to make clinical diagnosis more accessible and user-friendly, particularly in resource-limited settings. Their performance characteristics of high specificity, sensitivity, miniaturization, and ease of use make them excellent for the detection of a wide range of target analytes, including biomarkers for infectious diseases, cancer, and metabolic disorders. This review examines the different types of electrochemical nanobiosensors, their potential applications in low-cost clinical diagnosis, current challenges, and possible prospects. To solve the remaining issues and realize the full capacity of these technologies to improve healthcare access and affordability on a global level, we point out the importance of further research and development.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101205"},"PeriodicalIF":2.4,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.ijoes.2025.101203
Haoli Cheng , Yanchao Liang , Haiyan Yang , Dan Wang
Whereas this magnetic flux leakage classifier assured the safe operation of in-service pipelines, its magnetization impact might influence the corrosion behavior of pipeline steel, particularly for pipelines with flaws in service. In this paper, the weight loss method, AC impedance technique, potentiodynamic polarization technique, X-ray photoelectron spectroscopy (XPS), and finite element simulation were used to analyze the impact of magnetic field (MF) on the corrosion behavior of high-strength pipeline steel with V-Shaped Defects in Ku' erle simulated solution. The investigation revealed that the vertical MF enhanced corrosion near the end of such a V-Shaped Defect on the left in the Y-direction while inhibiting corrosion at the right end. And the perpendicular and parallel MF induced corrosion externally to the V-Shaped Defect while inhibiting corrosion within the V-Shaped Defect. Moreover, the effect of perpendicular and parallel MF on the corrosion system is mainly due to the effect of magnetic field gradient force, while the effect of vertical MF on the corrosion system is mainly due to the effect of Lorentz force.
{"title":"Effect of magnetic field on corrosion behavior of X70 pipeline steel with V-Shaped Defects","authors":"Haoli Cheng , Yanchao Liang , Haiyan Yang , Dan Wang","doi":"10.1016/j.ijoes.2025.101203","DOIUrl":"10.1016/j.ijoes.2025.101203","url":null,"abstract":"<div><div>Whereas this magnetic flux leakage classifier assured the safe operation of in-service pipelines, its magnetization impact might influence the corrosion behavior of pipeline steel, particularly for pipelines with flaws in service. In this paper, the weight loss method, AC impedance technique, potentiodynamic polarization technique, X-ray photoelectron spectroscopy (XPS), and finite element simulation were used to analyze the impact of magnetic field (MF) on the corrosion behavior of high-strength pipeline steel with V-Shaped Defects in Ku' erle simulated solution. The investigation revealed that the vertical MF enhanced corrosion near the end of such a V-Shaped Defect on the left in the Y-direction while inhibiting corrosion at the right end. And the perpendicular and parallel MF induced corrosion externally to the V-Shaped Defect while inhibiting corrosion within the V-Shaped Defect. Moreover, the effect of perpendicular and parallel MF on the corrosion system is mainly due to the effect of magnetic field gradient force, while the effect of vertical MF on the corrosion system is mainly due to the effect of Lorentz force.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101203"},"PeriodicalIF":2.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the growing demand for high-performance energy storage devices, the development of advanced electrode materials remains a critical challenge. Two-dimensional transition metal carbides (MXene) show great promise, yet their intrinsic tendency to restack in thin-film electrodes impedes ion transport and limits capacitance. Here, we propose a rational structural engineering strategy to overcome this limitation by constructing internally supported hierarchical porous Ti3C2Tx films through hard-template-assisted pore formation. Moreover, the in-situ polymerization of polyaniline nanowires within the pores enhances conductivity and provides additional pseudocapacitance. Benefiting from the synergistic effects of hierarchical porosity and conductive polymer integration, the optimized electrode delivers a high specific capacitance of 270 F g−1 at 0.2 A g−1 and an energy density of 37.5 Wh kg−1 at 200 W kg−1. After 8000 charge-discharge cycles, the capacitance retention remains at 80.37 %, demonstrating excellent stability. This work presents a simple and effective approach to designing robust MXene-based 3D porous electrodes, offering new insights into the development of high-performance supercapacitors.
随着对高性能储能器件的需求不断增长，开发先进的电极材料仍然是一个严峻的挑战。二维过渡金属碳化物（MXene）显示出很大的发展前景，但它们在薄膜电极中重新堆叠的固有倾向阻碍了离子传输并限制了电容。在这里，我们提出了一种合理的结构工程策略，通过硬模板辅助成孔来构建内部支撑的分层多孔Ti3C2Tx薄膜，以克服这一限制。此外，聚苯胺纳米线在孔内的原位聚合提高了电导率并提供了额外的伪电容。得益于分层孔隙度和导电聚合物集成的协同效应，优化后的电极在0.2 a g−1时具有270 F g−1的高比电容，在200 W kg−1时具有37.5 Wh kg−1的能量密度。在8000次充放电循环后，电容保持率保持在80.37 %，表现出良好的稳定性。这项工作提出了一种简单有效的方法来设计坚固的基于mxene的3D多孔电极，为高性能超级电容器的开发提供了新的见解。
{"title":"Hierarchical MXene/PANI porous film electrodes with improved ion transport for supercapacitors","authors":"Jiakun Liu, Zan Lu, Yuchen Jiang, Yantao Gao, Wei Liu, Wenfeng Hu, Binjie Xin","doi":"10.1016/j.ijoes.2025.101199","DOIUrl":"10.1016/j.ijoes.2025.101199","url":null,"abstract":"<div><div>With the growing demand for high-performance energy storage devices, the development of advanced electrode materials remains a critical challenge. Two-dimensional transition metal carbides (MXene) show great promise, yet their intrinsic tendency to restack in thin-film electrodes impedes ion transport and limits capacitance. Here, we propose a rational structural engineering strategy to overcome this limitation by constructing internally supported hierarchical porous Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> films through hard-template-assisted pore formation. Moreover, the in-situ polymerization of polyaniline nanowires within the pores enhances conductivity and provides additional pseudocapacitance. Benefiting from the synergistic effects of hierarchical porosity and conductive polymer integration, the optimized electrode delivers a high specific capacitance of 270 F g<sup>−1</sup> at 0.2 A g<sup>−1</sup> and an energy density of 37.5 Wh kg<sup>−1</sup> at 200 W kg<sup>−1</sup>. After 8000 charge-discharge cycles, the capacitance retention remains at 80.37 %, demonstrating excellent stability. This work presents a simple and effective approach to designing robust MXene-based 3D porous electrodes, offering new insights into the development of high-performance supercapacitors.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101199"},"PeriodicalIF":2.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-09DOI: 10.1016/j.ijoes.2025.101195
Roland Tolulope Loto, Sotom Victoria Tamunowari, Nim Ephraim Ekeruke, Enobong Deborah Udo, Joshua Oluwadamilola Ajayi, Fiyinfoluwa Mayowa Iyun, Joseph Ogbogu Kalu
This research investigates the sustainable corrosion inhibition of medium carbon steel (MCS) in 3.5 % NaCl solution, simulating seawater, using palm kernel oil (PKO), grapeseed oil (GS), and their 1:1 admixture (AD). Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffractometry (XRD) were employed to elucidate inhibition mechanisms. Uninhibited MCS exhibited a high corrosion rate (0.007 mm/y) and low polarization resistance (442 Ω). The AD formulation demonstrated the most effective performance, achieving 94.79 % inhibition efficiency at 1.5 % concentration, lowering the corrosion rate to 0.00036 mm/y and enhancing polarization resistance to 8568 Ω. EIS confirmed AD’s superior behavior, with Rp reaching 458,700 Ω at 3.5 %, indicating strong chemisorption and dense film formation. FTIR spectra revealed adsorption of O–H, CO, and C–O functional groups, with AD showing the strongest bonding interactions. XRD analysis further supported AD’s protective effect, with crystallite size reduced to 295 Å, evidencing robust surface modification. While PKO and GS also inhibited corrosion (67.23 % and 81.69 % efficiency at 2 % concentration, respectively), their protective films were less stable, with efficiency declining at higher concentrations due to film instability. OCP measurements indicated that GS at 3.5 % approached a pseudo-passive state (–0.786 V). The study establishes AD as a highly effective, green corrosion inhibitor, outperforming its individual components through synergistic interactions. These findings highlight the potential of plant-derived oils as eco-friendly alternatives to toxic inhibitors, supporting sustainable corrosion protection strategies for steel in chloride-rich environments.
{"title":"Investigation of corrosion inhibition of medium carbon steel using palm kernel and grapeseed oils in 3.5 % NaCl solution","authors":"Roland Tolulope Loto, Sotom Victoria Tamunowari, Nim Ephraim Ekeruke, Enobong Deborah Udo, Joshua Oluwadamilola Ajayi, Fiyinfoluwa Mayowa Iyun, Joseph Ogbogu Kalu","doi":"10.1016/j.ijoes.2025.101195","DOIUrl":"10.1016/j.ijoes.2025.101195","url":null,"abstract":"<div><div>This research investigates the sustainable corrosion inhibition of medium carbon steel (MCS) in 3.5 % NaCl solution, simulating seawater, using palm kernel oil (PKO), grapeseed oil (GS), and their 1:1 admixture (AD). Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffractometry (XRD) were employed to elucidate inhibition mechanisms. Uninhibited MCS exhibited a high corrosion rate (0.007 mm/y) and low polarization resistance (442 Ω). The AD formulation demonstrated the most effective performance, achieving 94.79 % inhibition efficiency at 1.5 % concentration, lowering the corrosion rate to 0.00036 mm/y and enhancing polarization resistance to 8568 Ω. EIS confirmed AD’s superior behavior, with Rp reaching 458,700 Ω at 3.5 %, indicating strong chemisorption and dense film formation. FTIR spectra revealed adsorption of O–H, C<img>O, and C–O functional groups, with AD showing the strongest bonding interactions. XRD analysis further supported AD’s protective effect, with crystallite size reduced to 295 Å, evidencing robust surface modification. While PKO and GS also inhibited corrosion (67.23 % and 81.69 % efficiency at 2 % concentration, respectively), their protective films were less stable, with efficiency declining at higher concentrations due to film instability. OCP measurements indicated that GS at 3.5 % approached a pseudo-passive state (–0.786 V). The study establishes AD as a highly effective, green corrosion inhibitor, outperforming its individual components through synergistic interactions. These findings highlight the potential of plant-derived oils as eco-friendly alternatives to toxic inhibitors, supporting sustainable corrosion protection strategies for steel in chloride-rich environments.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101195"},"PeriodicalIF":2.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-08DOI: 10.1016/j.ijoes.2025.101200
Yiwei Zhang , Longlong Guo , Limeng Yin , Zhenghua Deng , Xinyu Wang , Shaohu Liu
The influence of post weld heat treatment (PWHT) temperatures on the microstructure and corrosion resistance of laser cladded Inconel 625 coatings was investigated. The elements composition test indicates that the content of Fe changes sharply in the fusion zone between the coating and substrate, as well as overlap zone of coating layers. The microstructure observation shows that as welded Inconel 625 coating is mainly composed of columnar γ-Ni, Laves and seldom MC. The size of dendrites show an increase tendency with an increase in PWHT temperatures. There is no obvious difference in precipitates of the coating heat treated at 650℃ compared with the as welded. After heat treated at 750°C, a small amount of needle shaped δ phase precipitates. With a further increase in PWHT temperatures, a large number and continuous of δ phase forms, while the overall amount of δ phase seems to decrease when heat treated at 950°C. Electrochemical tests indicate that the (Rt), self corrosion potential (Ecorr), and pitting potential (Epit) show increase tendency, while self corrosion density (Icorr) shows opposite trend with an increase in PWHT temperatures less than 750℃. When the temperatures are larger than 850℃, Rt, Ecorr and Epit decrease, while Icorr increase. It is concluded that heat treated at temperatures not exceed 750℃ are benifit to improve resistance to initiate corrosion, uniform corrosion, and pitting.
{"title":"Effect of heat treatments on microstructure and corrosion resistance of laser-cladded Inconel 625 coatings","authors":"Yiwei Zhang , Longlong Guo , Limeng Yin , Zhenghua Deng , Xinyu Wang , Shaohu Liu","doi":"10.1016/j.ijoes.2025.101200","DOIUrl":"10.1016/j.ijoes.2025.101200","url":null,"abstract":"<div><div>The influence of post weld heat treatment (PWHT) temperatures on the microstructure and corrosion resistance of laser cladded Inconel 625 coatings was investigated. The elements composition test indicates that the content of <em>Fe</em> changes sharply in the fusion zone between the coating and substrate, as well as overlap zone of coating layers. The microstructure observation shows that as welded Inconel 625 coating is mainly composed of columnar γ-Ni, Laves and seldom MC. The size of dendrites show an increase tendency with an increase in PWHT temperatures. There is no obvious difference in precipitates of the coating heat treated at 650℃ compared with the as welded. After heat treated at 750°C, a small amount of needle shaped δ phase precipitates. With a further increase in PWHT temperatures, a large number and continuous of δ phase forms, while the overall amount of δ phase seems to decrease when heat treated at 950°C. Electrochemical tests indicate that the (<em>R</em><sub><em>t</em></sub>), self corrosion potential (<em>E</em><sub><em>corr</em></sub>), and pitting potential (<em>E</em><sub><em>pit</em></sub>) show increase tendency, while self corrosion density (<em>I</em><sub><em>corr</em></sub>) shows opposite trend with an increase in PWHT temperatures less than 750℃. When the temperatures are larger than 850℃, <em>R</em><sub><em>t</em></sub>, <em>E</em><sub><em>corr</em></sub> and <em>E</em><sub><em>pit</em></sub> decrease, while <em>I</em><sub><em>corr</em></sub> increase. It is concluded that heat treated at temperatures not exceed 750℃ are benifit to improve resistance to initiate corrosion, uniform corrosion, and pitting.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101200"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-08DOI: 10.1016/j.ijoes.2025.101201
Xuepeng Qi , Chaoyue Yang , Deying Mu , Wei Zhang , Li Zhao , Changsong Dai
The recycling and regeneration processes of spent LiFePO4 (SLFP) batteries have become a research hotspot due to their significant environmental and economic value. Current industrial recycling strategies for SLFP predominantly focus on improving lithium leaching rates, while paying less attention to the resulting ferric phosphate (FePO4) solid residues, leading to the waste of iron and phosphorus resources. Herein, we propose a closed-loop process for selectively leaching lithium (Li) from spent LFP batteries and regenerating new LFP cathode materials using the FePO4 from leaching residues. The spent LFP powder is co-ground in a combined hydrogen peroxide-citric acid (H2O2-H3Cit) solution system, with mechanical activation-assisted oxidative leaching, to achieve effective separation of lithium and iron under optimal conditions. The recovered FePO4 was purified and used to prepare new LiFePO4 cathode materials. The regenerated LiFePO4 materials show good electrochemical properties, with the discharge capacity of 144.42 mA h g−1 at 1 C and the capacity retention rate of 95.94 % after 200 cycles. After undergoing high-rate charge/discharge at 5 C and returning to 0.1 C rate, the discharge specific capacity remains stable at 127.24 mA h g−1. A closed-loop process route for spent LFP batteries consisting of "pretreatment-selective oxidative leaching-lithium carbonate and ferric phosphate (Li2CO3+FePO4)-regenerated LFP material" is established and it provides a reference idea and practical experience for the high-efficiency closed-loop development of LFP batteries.
废旧LiFePO4 （SLFP）电池的回收再生工艺因其具有重要的环境和经济价值而成为研究热点。目前SLFP的工业回收策略主要集中在提高锂的浸出率，而对产生的磷酸铁（FePO4）固体残留物关注较少，导致铁和磷资源的浪费。本文提出了一种闭环工艺，可以选择性地从废旧LFP电池中浸出锂（Li），并利用浸出残留物中的FePO4再生新的LFP正极材料。将废LFP粉末在双氧水-柠檬酸（H2O2-H3Cit）复合溶液体系中共磨，机械活化辅助氧化浸出，在最佳条件下实现锂铁的有效分离。对回收的FePO4进行了纯化，并用于制备LiFePO4正极材料。再生LiFePO4材料表现出良好的电化学性能，在1 ℃下放电容量为144.42 mA h g−1，循环200次后容量保持率为95.94 %。在5 C下进行高倍率充放电并恢复到0.1 C时，放电比容量稳定在127.24 mA h g−1。建立了“预处理-选择性氧化浸出-碳酸锂和磷酸铁(Li2CO3+FePO4)-再生LFP材料”的废LFP电池闭环工艺路线，为LFP电池的高效闭环开发提供了参考思路和实践经验。
{"title":"Selective oxidative leaching of Li+ and utilization of FePO4 for regeneration of LiFePO4 cathode material","authors":"Xuepeng Qi , Chaoyue Yang , Deying Mu , Wei Zhang , Li Zhao , Changsong Dai","doi":"10.1016/j.ijoes.2025.101201","DOIUrl":"10.1016/j.ijoes.2025.101201","url":null,"abstract":"<div><div>The recycling and regeneration processes of spent LiFePO<sub>4</sub> (SLFP) batteries have become a research hotspot due to their significant environmental and economic value. Current industrial recycling strategies for SLFP predominantly focus on improving lithium leaching rates, while paying less attention to the resulting ferric phosphate (FePO<sub>4</sub>) solid residues, leading to the waste of iron and phosphorus resources. Herein, we propose a closed-loop process for selectively leaching lithium (Li) from spent LFP batteries and regenerating new LFP cathode materials using the FePO<sub>4</sub> from leaching residues. The spent LFP powder is co-ground in a combined hydrogen peroxide-citric acid (H<sub>2</sub>O<sub>2</sub>-H<sub>3</sub>Cit) solution system, with mechanical activation-assisted oxidative leaching, to achieve effective separation of lithium and iron under optimal conditions. The recovered FePO<sub>4</sub> was purified and used to prepare new LiFePO<sub>4</sub> cathode materials. The regenerated LiFePO<sub>4</sub> materials show good electrochemical properties, with the discharge capacity of 144.42 mA h g<sup>−1</sup> at 1 C and the capacity retention rate of 95.94 % after 200 cycles. After undergoing high-rate charge/discharge at 5 C and returning to 0.1 C rate, the discharge specific capacity remains stable at 127.24 mA h g<sup>−1</sup>. A closed-loop process route for spent LFP batteries consisting of \"pretreatment-selective oxidative leaching-lithium carbonate and ferric phosphate (Li<sub>2</sub>CO<sub>3</sub>+FePO<sub>4</sub>)-regenerated LFP material\" is established and it provides a reference idea and practical experience for the high-efficiency closed-loop development of LFP batteries.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101201"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we propose a coupled electro-thermal model for simultaneous estimation of state-of-charge (SoC) and internal state-of-temperature (SoT) in lithium-ion battery cell. The electrical sub-model employs a temperature-aware first-order equivalent circuit model (ECM) whose parameters and the map are identified across eight temperatures from −25°C to 45°C, capturing strong thermo-electrochemical nonlinearities. For accuracy at low SoC, is modeled by two 10th-order polynomials split at 7 % SoC. SoC is inferred with a Kalman filter, then used to compute the cell heat input, which includes Joule heating and an entropic term ; drives a compact autoregressive with extra input (ARX) thermal model whose coefficients depend on ambient temperature to yield SoT. In experiments on a Samsung 18650–35E cell, the method achieves RMSE of 0.0079°C between the ARX thermal model’s SoT estimate and an independently measured temperature reference obtained using a micro T-type thermocouple (∼80 µm in diameter) embedded inside the cell, substantially lower than a recent Pearson-correlation deep model (0.097°C), while achieving SoC RMSE = 1.96 % with markedly lower computational burden than UKF variants, making it suitable for low-cost battery management system (BMS). The ECM terminal-voltage RMSE remains small (lowest at −5°C: 0.074; highest at 45°C: 0.363), reflecting temperature-dependent dynamics captured by the model. Overall, the novelty lies in: (i) full temperature-dependence of ECM parameters and over a wide thermal range, (ii) an ARX-based SoT estimator explicitly fed by physics-informed , and (iii) a single-Kalman Filter–ARX pipeline that balances accuracy and real-time applicability on resource-constrained hardware.
{"title":"Simultaneous estimation of state-of-charge and state-of-temperature in lithium-ion batteries using a coupled electro-thermal model","authors":"Thanh Ngo Phuong , Thuy Nguyen Vinh , Chi Nguyen Van , Minh Duc Ngo , Seon-Ju Ahn , Member, IEEE","doi":"10.1016/j.ijoes.2025.101202","DOIUrl":"10.1016/j.ijoes.2025.101202","url":null,"abstract":"<div><div>In this paper, we propose a coupled electro-thermal model for simultaneous estimation of state-of-charge (SoC) and internal state-of-temperature (SoT) in lithium-ion battery cell. The electrical sub-model employs a temperature-aware first-order equivalent circuit model (ECM) whose parameters and the <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mtext>OC</mtext></mrow></msub><mo>(</mo><mi>SoC</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> map are identified across eight temperatures from −25°C to 45°C, capturing strong thermo-electrochemical nonlinearities. For accuracy at low SoC, <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mtext>OC</mtext></mrow></msub><mo>(</mo><mi>SoC</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> is modeled by two 10th-order polynomials split at 7 % SoC. SoC is inferred with a Kalman filter, then used to compute the cell heat input<span><math><mrow><mspace></mspace><mi>d</mi><msub><mrow><mi>q</mi></mrow><mrow><mi>cell</mi></mrow></msub><mo>/</mo><mi>dt</mi></mrow></math></span>, which includes Joule heating and an entropic term <span><math><mrow><mo>∂</mo><msub><mrow><mi>V</mi></mrow><mrow><mtext>OC</mtext></mrow></msub><mo>/</mo><mo>∂</mo><mi>T</mi></mrow></math></span>; <span><math><mrow><mi>d</mi><msub><mrow><mi>q</mi></mrow><mrow><mi>cell</mi></mrow></msub><mo>/</mo><mi>dt</mi></mrow></math></span> drives a compact autoregressive with extra input (ARX) thermal model whose coefficients depend on ambient temperature to yield SoT. In experiments on a Samsung 18650–35E cell, the method achieves RMSE of 0.0079°C between the ARX thermal model’s SoT estimate and an independently measured temperature reference obtained using a micro T-type thermocouple (∼80 µm in diameter) embedded inside the cell, substantially lower than a recent Pearson-correlation deep model (0.097°C), while achieving SoC RMSE = 1.96 % with markedly lower computational burden than UKF variants, making it suitable for low-cost battery management system (BMS). The ECM terminal-voltage RMSE remains small (lowest at −5°C: 0.074; highest at 45°C: 0.363), reflecting temperature-dependent dynamics captured by the model. Overall, the novelty lies in: (i) full temperature-dependence of ECM parameters and <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mtext>OC</mtext></mrow></msub><mo>(</mo><mi>SoC</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> over a wide thermal range, (ii) an ARX-based SoT estimator explicitly fed by physics-informed <span><math><mrow><mi>d</mi><msub><mrow><mi>q</mi></mrow><mrow><mi>cell</mi></mrow></msub><mo>/</mo><mi>dt</mi></mrow></math></span>, and (iii) a single-Kalman Filter–ARX pipeline that balances accuracy and real-time applicability on resource-constrained hardware.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"20 11","pages":"Article 101202"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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