Pub Date : 2025-12-08DOI: 10.1016/j.electacta.2025.147983
Durgambika Venkatachalam, Yoganandan Govindaraj, J. Manoj Prabhakar, Arulkumar Ganapathi, Masatoshi Sakairi, Michael Rohwerder, Lakshman Neelakantan
In this study, a self-healing zinc (Zn) coating incorporating pH-responsive SBA-15-BTA-PDDA particles was electro-co-deposited onto high-strength steel (HSS). Two different particle concentrations in the bath have been considered and named Zn-1 (1000 ppm) and Zn-2 (15000 ppm) for the optimisation of coating. The SEM and cross-sectional micrographs confirm the incorporation of particles in the zinc matrix. From the electrochemical analysis, in comparison to the bare Zn, Zn-1 and Zn-2 coatings, Zn-1 exhibits superior corrosion resistance. From EIS, after 168 h of immersion, the charge transfer resistance (Rct) of Zn-1 is 387.07±4 Ω cm2, approximately a healing factor of 20, which is 6 times higher than that of Zn; the corrosion current density (icorr) is approximately 50 % lower than that of Zn. This improved inhibition performance is attributed to the addition of SBA-15-BTA-PDDA particles, which release the inhibitor BTA in response to the local pH change, thereby effectively enhancing the corrosion resistance of the coating. However, increased concentration in Zn-2 results in forming agglomerates and defects, leading to inhomogeneities on the coating surface, or the particles themselves can act as cathodic sites. In addition, the coating exhibits improved self-healing properties. Rct values observed from the EIS analysis, after the accelerated study, corroborated the results made in immersion studies, where Zn-1 shows improved resistance compared to Zn, which is due to the synergistic performance of corrosion protection and self-healing action.
{"title":"pH-responsive self-healing zinc composite coatings for long-term corrosion protection of steels","authors":"Durgambika Venkatachalam, Yoganandan Govindaraj, J. Manoj Prabhakar, Arulkumar Ganapathi, Masatoshi Sakairi, Michael Rohwerder, Lakshman Neelakantan","doi":"10.1016/j.electacta.2025.147983","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147983","url":null,"abstract":"In this study, a self-healing zinc (Zn) coating incorporating pH-responsive SBA-15-BTA-PDDA particles was electro-co-deposited onto high-strength steel (HSS). Two different particle concentrations in the bath have been considered and named Zn-1 (1000 ppm) and Zn-2 (15000 ppm) for the optimisation of coating. The SEM and cross-sectional micrographs confirm the incorporation of particles in the zinc matrix. From the electrochemical analysis, in comparison to the bare Zn, Zn-1 and Zn-2 coatings, Zn-1 exhibits superior corrosion resistance. From EIS, after 168 h of immersion, the charge transfer resistance (R<sub>ct</sub>) of Zn-1 is 387.07±4 Ω cm<sup>2</sup>, approximately a healing factor of 20, which is 6 times higher than that of Zn; the corrosion current density (i<sub>corr</sub>) is approximately 50 % lower than that of Zn. This improved inhibition performance is attributed to the addition of SBA-15-BTA-PDDA particles, which release the inhibitor BTA in response to the local pH change, thereby effectively enhancing the corrosion resistance of the coating. However, increased concentration in Zn-2 results in forming agglomerates and defects, leading to inhomogeneities on the coating surface, or the particles themselves can act as cathodic sites. In addition, the coating exhibits improved self-healing properties. R<sub>ct</sub> values observed from the EIS analysis, after the accelerated study, corroborated the results made in immersion studies, where Zn-1 shows improved resistance compared to Zn, which is due to the synergistic performance of corrosion protection and self-healing action.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"142 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Designing and developing high-activity and long-term durability electrocatalysts for the oxygen evolution reaction (OER) has primary significance for breaking the bottleneck of water electrolysis. In this study, we synthesized a series of halogen-doped cerium–iron heterostructures with abundant oxygen vacancies on the surface of nickel foam using a simple hydrothermal method. In this structure, the conversion between Ce3+ and Ce4+ in CeO2 generates abundant oxygen vacancies that effectively enhance catalyst activity. Concurrently, the combination of the heterostructure and anion doping design synergistically lowers the reaction energy barrier to boost catalytic activity, enabling robust kinetics for the OER reaction. Electrochemical tests demonstrated that the Br-CeO2/FeS-NF catalyst exhibited excellent OER performance in 1.0 M KOH solution, with an overpotential of only 204 mV at a current density of 10 mA·cm-2 and a Tafel slope of 31.6 mV·dec-1. Meanwhile, the catalyst exhibited good long-term stability in alkaline electrolyte, with an operational stability of 72 h at 100 mA·cm-2.
设计和开发高活性、长效的析氧反应电催化剂对于突破水电解瓶颈具有重要意义。在本研究中，我们利用简单的水热法在泡沫镍表面合成了一系列具有丰富氧空位的卤素掺杂铈铁异质结构。在这种结构中，CeO2中Ce3+和Ce4+的转化产生了丰富的氧空位，有效地提高了催化剂的活性。同时，异质结构和阴离子掺杂设计的结合协同降低了反应能垒，提高了催化活性，使OER反应的动力学更加稳健。电化学测试表明，Br-CeO2/FeS-NF催化剂在1.0 M KOH溶液中表现出优异的OER性能，在电流密度为10 mA·cm-2时过电位仅为204 mV， Tafel斜率为31.6 mV·dec1。同时，该催化剂在碱性电解质中表现出良好的长期稳定性，在100 mA·cm-2下的运行稳定性为72 h。
{"title":"Construction of X-CeO2/FeS heterointerfaces via halogen doping for accelerated oxygen evolution electrocatalysis","authors":"Yanhuan Wang, Li Li, Tishi Shen, Qingchun Han, Ling Hai, Yujuan Zhai","doi":"10.1016/j.electacta.2025.147984","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147984","url":null,"abstract":"Designing and developing high-activity and long-term durability electrocatalysts for the oxygen evolution reaction (OER) has primary significance for breaking the bottleneck of water electrolysis. In this study, we synthesized a series of halogen-doped cerium–iron heterostructures with abundant oxygen vacancies on the surface of nickel foam using a simple hydrothermal method. In this structure, the conversion between Ce<sup>3+</sup> and Ce<sup>4+</sup> in CeO<sub>2</sub> generates abundant oxygen vacancies that effectively enhance catalyst activity. Concurrently, the combination of the heterostructure and anion doping design synergistically lowers the reaction energy barrier to boost catalytic activity, enabling robust kinetics for the OER reaction. Electrochemical tests demonstrated that the Br-CeO<sub>2</sub>/FeS-NF catalyst exhibited excellent OER performance in 1.0 M KOH solution, with an overpotential of only 204 mV at a current density of 10 mA·cm<sup>-2</sup> and a Tafel slope of 31.6 mV·dec<sup>-1</sup>. Meanwhile, the catalyst exhibited good long-term stability in alkaline electrolyte, with an operational stability of 72 h at 100 mA·cm<sup>-2</sup>.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"4 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-08DOI: 10.1016/j.electacta.2025.147985
Max Stevenson, Michael König, Ina Klein, Radha Boya, Jürgen Senker, Markus Retsch, Josef Breu
Coplanar microelectrodes, particularly interdigitated electrodes (IDEs), are widely employed in electrochemical sensing owing to low cost, scalable fabrication, and high surface sensitivity. However, accurate and quantitative interpretation requires precise determination of the cell constant (k). This becomes nontrivial when the electrode's electric field is only partially immersed in the electrolyte, as is common in thin film or confined-volume systems. This work presents a fast, reproducible, and low-cost experimental platform for measuring film thickness-dependent correction factors (α) of k. Electrochemical impedance spectroscopy (EIS) was applied on printed circuit board (PCB) IDEs comprising five different electrode finger widths (w) and spacings (s) (w = s: 250 µm, 500 µm, 1000 µm, 1500 µm, and 2000 µm). k was determined while fully immersed, and α was subsequently empirically derived as a function of electrolyte film thickness (α(d)). The results were compared to finite element methods (FEM; COMSOL), revealing consistent trends but notable deviations in absolute values of α(d). These findings highlight the limitations of simplified field models and provide a practical approach for a more accurate characterization of thin films on coplanar electrodes.
{"title":"A Practical Approach to Thickness-Dependent Cell Constant Correction for Coplanar or Interdigitated Electrodes","authors":"Max Stevenson, Michael König, Ina Klein, Radha Boya, Jürgen Senker, Markus Retsch, Josef Breu","doi":"10.1016/j.electacta.2025.147985","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147985","url":null,"abstract":"Coplanar microelectrodes, particularly interdigitated electrodes (IDEs), are widely employed in electrochemical sensing owing to low cost, scalable fabrication, and high surface sensitivity. However, accurate and quantitative interpretation requires precise determination of the cell constant (<em>k</em>). This becomes nontrivial when the electrode's electric field is only partially immersed in the electrolyte, as is common in thin film or confined-volume systems. This work presents a fast, reproducible, and low-cost experimental platform for measuring film thickness-dependent correction factors (<em>α</em>) of <em>k</em>. Electrochemical impedance spectroscopy (EIS) was applied on printed circuit board (PCB) IDEs comprising five different electrode finger widths (<em>w</em>) and spacings (<em>s</em>) (<em>w</em> = <em>s</em>: 250 µm, 500 µm, 1000 µm, 1500 µm, and 2000 µm). <em>k</em> was determined while fully immersed, and <em>α</em> was subsequently empirically derived as a function of electrolyte film thickness (<em>α</em>(<em>d</em>)). The results were compared to finite element methods (FEM; COMSOL), revealing consistent trends but notable deviations in absolute values of <em>α</em>(<em>d</em>). These findings highlight the limitations of simplified field models and provide a practical approach for a more accurate characterization of thin films on coplanar electrodes.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"4 4 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1016/j.electacta.2025.147970
Ling Zhang, Wenna Xie, Yan Yan, Jiahao Wang, Jin Li, Mi Ouyang, Yujie Dong, Weijun Li, Cheng Zhang
The impact of isomerism on electrochemical/electrochromic (EC) materials remains insufficiently explored. In this work, two electrochromic-supercapacitor (ECS) bifunctional materials pBQ based on pyrazine unit and pDQ based on pyridazine unit featuring diazine isomers are synthesized through direct (hetero)arylation polymerization. The impact of diazine isomeric units on backbone structure, EC properties, and supercapacitor performance of materials are investigated in detail. The pBQ base on pyrazine displays enhanced backbone planarity, higher color saturation of 51.82 in the neutral state and lower color chroma of 0.26 in the oxidized state, indicating reversible color-changing between a more vivid colored state and highly transparent state. Furthermore, the pBQ presents improved electrochemical and EC properties than those of pDQ, including more reversible electrochemical behavior, larger coloring efficiency (279.5 cm²/C), better cycle stability (retaining >90% of initial performance after 1000 cycles), and higher area-specific capacitance of 2.61 mF/cm. The prototype EC labels base on pBQ and pDQ are assembled, enabling updatable information capabilities and dynamic data management. This work introduces a novel approach to precisely enhance backbone planarity, facilitate color tunability, and develop electrochromic-supercapacitor bifunctional materials with high-performance.
{"title":"The tunable electrochromic and energy storage performances of bifunctional materials based on diazine isomeric units","authors":"Ling Zhang, Wenna Xie, Yan Yan, Jiahao Wang, Jin Li, Mi Ouyang, Yujie Dong, Weijun Li, Cheng Zhang","doi":"10.1016/j.electacta.2025.147970","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147970","url":null,"abstract":"The impact of isomerism on electrochemical/electrochromic (EC) materials remains insufficiently explored. In this work, two electrochromic-supercapacitor (ECS) bifunctional materials <strong>pBQ</strong> based on pyrazine unit and <strong>pDQ</strong> based on pyridazine unit featuring diazine isomers are synthesized through direct (hetero)arylation polymerization. The impact of diazine isomeric units on backbone structure, EC properties, and supercapacitor performance of materials are investigated in detail. The <strong>pBQ</strong> base on pyrazine displays enhanced backbone planarity, higher color saturation of 51.82 in the neutral state and lower color chroma of 0.26 in the oxidized state, indicating reversible color-changing between a more vivid colored state and highly transparent state. Furthermore, the <strong>pBQ</strong> presents improved electrochemical and EC properties than those of <strong>pDQ</strong>, including more reversible electrochemical behavior, larger coloring efficiency (279.5 cm²/C), better cycle stability (retaining >90% of initial performance after 1000 cycles), and higher area-specific capacitance of 2.61 mF/cm. The prototype EC labels base on <strong>pBQ</strong> and <strong>pDQ</strong> are assembled, enabling updatable information capabilities and dynamic data management. This work introduces a novel approach to precisely enhance backbone planarity, facilitate color tunability, and develop electrochromic-supercapacitor bifunctional materials with high-performance.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"26 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1016/j.electacta.2025.147973
Gabriella S. Limeira, Lucas V. Bertolim, Arielly Cardoso, Jéssica R. Camargo, Rafael M. Dornellas, Leonardo F. Fraceto, Bruno C. Janegitz
The versatility and broad applicability of 3D printing technology have made this tool increasingly prominent across various scientific and industrial fields. In particular, the development of novel conductive filaments has significantly contributed to advances in the fabrication of high-performance electrochemical devices. In this study, we report the development of a 3D-printed electrochemical sensor using a lab-fabricated filament composed of carbon black (CB), polypropylene (PP), polylactic acid (PLA), and coconut oil, designed for the detection of the insecticide carbaryl in water samples. The composite material (CB-PP-PLA-coconut oil) was prepared through a melt-mixing and grinding process, followed by filament extrusion and sensor fabrication using fused deposition modeling (FDM) technology. The resulting electrodes were characterized using scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). However, it was found that mechanical polishing alone was sufficient to ensure efficient sensor operation. Carbaryl detection was performed using square wave voltammetry (SWV), yielding a linear response in the concentration range of 1.0 –100.0 µmol L⁻¹, with a detection limit of 0.25 µmol L⁻¹ and recovery rates between 90% and 110% in spiked water samples. These results demonstrate that the 3D-printed CB-PP-PLA-coconut oil sensor represents a promising, low-cost, and sustainable platform for environmental monitoring, with potential applications in detecting various chemical contaminants.
{"title":"Development of a 3D-Printed Electrochemical Sensor with Carbon Black, Polypropylene, Polylactic Acid, and Coconut Oil Filament for Carbaryl Detection","authors":"Gabriella S. Limeira, Lucas V. Bertolim, Arielly Cardoso, Jéssica R. Camargo, Rafael M. Dornellas, Leonardo F. Fraceto, Bruno C. Janegitz","doi":"10.1016/j.electacta.2025.147973","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147973","url":null,"abstract":"The versatility and broad applicability of 3D printing technology have made this tool increasingly prominent across various scientific and industrial fields. In particular, the development of novel conductive filaments has significantly contributed to advances in the fabrication of high-performance electrochemical devices. In this study, we report the development of a 3D-printed electrochemical sensor using a lab-fabricated filament composed of carbon black (CB), polypropylene (PP), polylactic acid (PLA), and coconut oil, designed for the detection of the insecticide carbaryl in water samples. The composite material (CB-PP-PLA-coconut oil) was prepared through a melt-mixing and grinding process, followed by filament extrusion and sensor fabrication using fused deposition modeling (FDM) technology. The resulting electrodes were characterized using scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). However, it was found that mechanical polishing alone was sufficient to ensure efficient sensor operation. Carbaryl detection was performed using square wave voltammetry (SWV), yielding a linear response in the concentration range of 1.0 –100.0 µmol L⁻¹, with a detection limit of 0.25 µmol L⁻¹ and recovery rates between 90% and 110% in spiked water samples. These results demonstrate that the 3D-printed CB-PP-PLA-coconut oil sensor represents a promising, low-cost, and sustainable platform for environmental monitoring, with potential applications in detecting various chemical contaminants.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"217 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145697325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1016/j.electacta.2025.147977
Nicci L. Fröhlich, Hanna Sjö, Francesc Valls Mascaró, Marc T.M. Koper
Platinum electrodes are of key importance in electrocatalysis due to their high activity for the hydrogen evolution and oxygen reduction reactions. Industrially-relevant Pt electrodes typically exhibit significant surface heterogeneity (i.e., poly-/nanocrystallinity), complicating the establishment of clear relationships between structure and electrochemical properties. To unravel the influence of surface structure on interfacial properties at a fundamental level, two key electrochemical parameters are studied here: the potential of zero total charge (Epztc) and the “double-layer” capacity (Cdl). Using a combination of cyclic voltammetry, electrochemical impedance spectroscopy, and ex situ electron backscatter diffraction, the electrochemical responses of three different polycrystalline Pt electrodes are compared and correlated with their respective facet orientation distributions. We show that, despite significant surface complexity, the Epztc and Cdl remain highly sensitive to local facet orientations, mirroring trends previously observed for model stepped single-crystal Pt surfaces. In particular, (100)-type sites dominate the capacitance response in the so-called “double-layer” region (between 0.40 – 0.60 VRHE), due to pseudocapacitive contributions resulting from a potential-dependent OHads coverage. These findings confirm that the structure-sensitivity of electrochemical properties previously identified for model systems can be predictably extended to polycrystalline Pt electrodes and provides a fundamental insight into macroscopic electrochemical behavior based on microscopic surface features.
{"title":"Correlating Surface Structure and Electrochemical Properties of Polycrystalline Platinum Electrodes","authors":"Nicci L. Fröhlich, Hanna Sjö, Francesc Valls Mascaró, Marc T.M. Koper","doi":"10.1016/j.electacta.2025.147977","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147977","url":null,"abstract":"Platinum electrodes are of key importance in electrocatalysis due to their high activity for the hydrogen evolution and oxygen reduction reactions. Industrially-relevant Pt electrodes typically exhibit significant surface heterogeneity (<ce:italic>i.e.</ce:italic>, poly-/nanocrystallinity), complicating the establishment of clear relationships between structure and electrochemical properties. To unravel the influence of surface structure on interfacial properties at a fundamental level, two key electrochemical parameters are studied here: the potential of zero total charge (<ce:italic>E</ce:italic><ce:inf loc=\"post\">pztc</ce:inf>) and the “double-layer” capacity (<ce:italic>C</ce:italic><ce:inf loc=\"post\">dl</ce:inf>). Using a combination of cyclic voltammetry, electrochemical impedance spectroscopy, and <ce:italic>ex situ</ce:italic> electron backscatter diffraction, the electrochemical responses of three different polycrystalline Pt electrodes are compared and correlated with their respective facet orientation distributions. We show that, despite significant surface complexity, the <ce:italic>E</ce:italic><ce:inf loc=\"post\">pztc</ce:inf> and <ce:italic>C</ce:italic><ce:inf loc=\"post\">dl</ce:inf> remain highly sensitive to local facet orientations, mirroring trends previously observed for model stepped single-crystal Pt surfaces. In particular, (100)-type sites dominate the capacitance response in the so-called “double-layer” region (between 0.40 – 0.60 V<ce:inf loc=\"post\">RHE</ce:inf>), due to pseudocapacitive contributions resulting from a potential-dependent OH<ce:inf loc=\"post\">ads</ce:inf> coverage. These findings confirm that the structure-sensitivity of electrochemical properties previously identified for model systems can be predictably extended to polycrystalline Pt electrodes and provides a fundamental insight into macroscopic electrochemical behavior based on microscopic surface features.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"3 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145697326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clean energy is essential to achieving the United Nations' Sustainable Development Goals and targets. Proton Exchange Membrane Fuel Cells (PEMFCs) are one of the leading technologies for implementing the "hydrogen economy" and contributing to a sustainable energy supply. PEMFC development requires high-performing, durable electrocatalysts (ECs) whose synthesis is as facile and inexpensive as possible. This work demonstrates that it is feasible to synthesize viable ECs for PEMFCs from platinum mining residues obtained in Colombia. This Pt source is hardly exploited and, in perspective, could offer a lower-cost alternative to more established precursors for the preparation of ECs for PEMFCs. In particular, the ECs considered in this work are intended to promote the oxygen reduction reaction (ORR), a key bottleneck in PEMFC operation. The precursors from mining residues were characterized by micro-Raman, ATR-FTIR, XRD, TGA, and SEM/EDS to clarify their chemical composition and identify the coordination complexes present therein. Two synthetic methods are considered: (i) the microemulsion method; and (ii) the polyol method. A statistical Design of Experiments (DoE) is implemented to determine the optimal experimental conditions for each synthetic method. The physicochemical properties of the resulting Pt/C ECs are elucidated by SEM, TEM/STEM-EDS, XRD, and XPS. Finally, it is found that the "ex-situ" ORR performance determined by the CV-TF-RRDE method of the Pt/C ECs presented in this work compares favorably to that of a state-of-the-art Pt/C EC benchmark for the ORR.
{"title":"Beyond Pure Precursors: Towards Oxygen Reduction Reaction Activity Enhancement in PEM Fuel Cells from Recycled Mining Waste","authors":"Diana Orozco-Gallo, Ricardo Ossa-Gallego, Catalina Orozco-Silva, Verónica Muñoz-Montes, Soufiane Boudjelida, Gioele Pagot, Enrico Negro, Vito Di Noto, Jorge Calderón-Gutiérrez","doi":"10.1016/j.electacta.2025.147979","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.147979","url":null,"abstract":"Clean energy is essential to achieving the United Nations' Sustainable Development Goals and targets. Proton Exchange Membrane Fuel Cells (PEMFCs) are one of the leading technologies for implementing the \"hydrogen economy\" and contributing to a sustainable energy supply. PEMFC development requires high-performing, durable electrocatalysts (ECs) whose synthesis is as facile and inexpensive as possible. This work demonstrates that it is feasible to synthesize viable ECs for PEMFCs from platinum mining residues obtained in Colombia. This Pt source is hardly exploited and, in perspective, could offer a lower-cost alternative to more established precursors for the preparation of ECs for PEMFCs. In particular, the ECs considered in this work are intended to promote the oxygen reduction reaction (ORR), a key bottleneck in PEMFC operation. The precursors from mining residues were characterized by micro-Raman, ATR-FTIR, XRD, TGA, and SEM/EDS to clarify their chemical composition and identify the coordination complexes present therein. Two synthetic methods are considered: (i) the microemulsion method; and (ii) the polyol method. A statistical Design of Experiments (DoE) is implemented to determine the optimal experimental conditions for each synthetic method. The physicochemical properties of the resulting Pt/C ECs are elucidated by SEM, TEM/STEM-EDS, XRD, and XPS. Finally, it is found that the <ce:italic>\"ex-situ\"</ce:italic> ORR performance determined by the CV-TF-RRDE method of the Pt/C ECs presented in this work compares favorably to that of a state-of-the-art Pt/C EC benchmark for the ORR.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"11 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145697320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1016/j.electacta.2025.147978
Letícia C.F. de Oliveira, Matheus Santos, Antonio A.S. Curvelo, André H.B. Dourado, Hamilton Varela
Electrobiorefinery is a green alternative for new feedstocks, such as lignocellulosic biomass from industry, can be turned into high value-added products, by electrocatalytic processes, which efficiently converts electric energy into chemical bonds. In the present work, lignin electrochemical oxidation reaction (LEOR) was investigated on Ni surfaces, and the morphology and temperature were evaluated. First, macromorphology was investigated, using plate and foam electrodes. The first was more active, (current is around 3 times higher) while the second was more selective (16.42 vs. 23.97% Faradaic Efficiency (FE) for total aldehydes and 24.02 vs. 37.74 % FE for total ketones, plate vs. foam at 1.40 VRHE), differences that were rationalized by the presence of desorbed intermediates and mass transport properties. In situ Raman spectroscopy has shown that, even with these differences, the same reaction was taking place, and that the disorganized γ-NiOOH, was the preferential Ni active species, unexpectedly considering the literature knowledge for oxygen evolution reaction on Ni based material. Mild temperatures were more selective, but the electrochemical kinetic limitations were unchanged with the temperature, showing that the rate limiting step would be the first oxidative one, which generate radical intermediates.
电生物炼制是一种绿色的新原料替代品，例如来自工业的木质纤维素生物质，可以通过电催化过程转化为高附加值的产品，该过程有效地将电能转化为化学键。本文研究了木质素在Ni表面的电化学氧化反应，并对其形貌和温度进行了评价。首先，采用板电极和泡沫电极进行宏观形貌研究。前者更活跃（电流大约是前者的3倍），而后者更具选择性（总醛的法拉第效率（FE）为16.42 vs. 23.97%，总酮的法拉第效率（FE）为24.02 vs. 37.74%，平板与泡沫在1.40 VRHE），差异被解吸中间体的存在和质量传输特性所合理解释。原位拉曼光谱显示，即使存在这些差异，相同的反应也发生了，并且考虑到Ni基材料上的析氧反应的文献知识，无序的γ-NiOOH是优先的Ni活性物质。温和温度选择性更强，但电化学动力学限制随温度不变，表明限速步骤为第一氧化步骤，生成自由基中间体。
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Pub Date : 2025-12-07DOI: 10.1016/j.electacta.2025.147969
Wenhao Li, Siqi Wang, Han Li, Yuanhe Tian, Jingqi Zhang, Yi Zhao, Xiaogeng Huo, Faqiang Li, Chunfeng Hu
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