Pub Date : 2026-01-01Epub Date: 2025-11-21DOI: 10.1016/j.ijoes.2025.101250
Dina Thole , Kwena D. Modibane , Reineck Mhlaba , Sheriff A. Balogun , Ebrahiem Botha , Collen L. Makola , Nicholas M. Musyoka
Investigating new, effective, and useful catalysts continues to be a research and industrial need as the world's hunt for sustainable energy continues to grow. In particular, it has been demonstrated that metal-organic frameworks support the capture and electrochemical reversible reaction of CO₂-to-formic acid, with remarkable CO₂ capture capabilities. We present here the photocatalytic hydrogen production activity of a quaternary structure made up of bimetallic oxides, metal-organic frameworks, and carbon nanotubes. Comprehensive structure–performance correlations for the development of effective photocatalysts are provided by detailed characterization before and after catalysis. The best performance is shown by the quaternary composite, which achieves 99.9 % hydrogen selectivity with carbon dioxide capture and produces 21.2 mmol/g of hydrogen at a rate of 220 μmol/g/min. The present paper offers a promising approach to develop highly efficient and cost-effective low-dimensional photoelectrocatalysts for sustainable hydrogen production from formic acid with CO2 capture, potentially tackling the challenges posed by the climate crisis.
{"title":"Carbon nanotube/Bimetallic oxide-Copper-MOF (PdO-NiO-Cu-MOF-MWCNTs) composite for efficient hydrogen production from formic acid coupled with CO₂ utilization","authors":"Dina Thole , Kwena D. Modibane , Reineck Mhlaba , Sheriff A. Balogun , Ebrahiem Botha , Collen L. Makola , Nicholas M. Musyoka","doi":"10.1016/j.ijoes.2025.101250","DOIUrl":"10.1016/j.ijoes.2025.101250","url":null,"abstract":"<div><div>Investigating new, effective, and useful catalysts continues to be a research and industrial need as the world's hunt for sustainable energy continues to grow. In particular, it has been demonstrated that metal-organic frameworks support the capture and electrochemical reversible reaction of CO₂-to-formic acid, with remarkable CO₂ capture capabilities. We present here the photocatalytic hydrogen production activity of a quaternary structure made up of bimetallic oxides, metal-organic frameworks, and carbon nanotubes. Comprehensive structure–performance correlations for the development of effective photocatalysts are provided by detailed characterization before and after catalysis. The best performance is shown by the quaternary composite, which achieves 99.9 % hydrogen selectivity with carbon dioxide capture and produces 21.2 mmol/g of hydrogen at a rate of 220 μmol/g/min. The present paper offers a promising approach to develop highly efficient and cost-effective low-dimensional photoelectrocatalysts for sustainable hydrogen production from formic acid with CO<sub>2</sub> capture, potentially tackling the challenges posed by the climate crisis.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101250"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571101","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 : 2026-01-01Epub Date: 2025-11-10DOI: 10.1016/j.ijoes.2025.101230
Jiantao Wang, Bochen Jiang
This study systematically investigates the corrosion behavior of DH36 steel under the combined influence of chloride (Cl⁻) and hydrogen (H⁺) ions, simulating marine splash zone environments. Electrochemical techniques—including potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS)—coupled with microstructural analyses (SEM and EDS) were employed to evaluate corrosion mechanisms in NaCl solutions (1–7.5 wt%) and in acidic solutions containing 3.5 wt% NaCl with HCl concentrations ranging from 0 to 0.6 mol/L. Results reveal that with increasing Cl− concentration, the corrosion potential decreases from − 519 mV to − 588 mV and the corrosion current density increases from 0.0137 mA/cm² to 0.0279 mA/cm², indicating accelerated corrosion rates. Notably, at > 5 wt% NaCl, pit density surges to 11,440 pits/mm² (7.5 wt%), while pit size expands by ∼ 80 %. In acidic Cl⁻-rich environments (HCl ≥ 0.4 mol/L), corrosion intensifies, and corrosion products become porous, facilitating longitudinal grooves and deep pits. EIS data confirm decreased polarization resistance (e.g., Rp drops from 4211 Ω·cm² to 2297 Ω·cm² in 7.5 wt% NaCl), and Warburg impedance emerges, signifying diffusion-controlled corrosion. The dominant mechanism involves electrochemical reactions where Cl⁻ and H⁺ act in concert to aggressively promote Fe dissolution via soluble complexes (e.g., [FeCl(OH)]⁻ad), while acidic conditions inhibit passivation. These findings highlight the critical vulnerability of DH36 steel in aggressive marine settings, providing essential insights for enhancing corrosion resistance in offshore structures.
{"title":"Investigation of the effect of chloride ions on the corrosion of DH36 steel in acidic solution","authors":"Jiantao Wang, Bochen Jiang","doi":"10.1016/j.ijoes.2025.101230","DOIUrl":"10.1016/j.ijoes.2025.101230","url":null,"abstract":"<div><div>This study systematically investigates the corrosion behavior of DH36 steel under the combined influence of chloride (Cl⁻) and hydrogen (H⁺) ions, simulating marine splash zone environments. Electrochemical techniques—including potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS)—coupled with microstructural analyses (SEM and EDS) were employed to evaluate corrosion mechanisms in NaCl solutions (1–7.5 wt%) and in acidic solutions containing 3.5 wt% NaCl with HCl concentrations ranging from 0 to 0.6 mol/L. Results reveal that with increasing Cl<sup>−</sup> concentration, the corrosion potential decreases from − 519 mV to − 588 mV and the corrosion current density increases from 0.0137 mA/cm² to 0.0279 mA/cm², indicating accelerated corrosion rates. Notably, at > 5 wt% NaCl, pit density surges to 11,440 pits/mm² (7.5 wt%), while pit size expands by ∼ 80 %. In acidic Cl⁻-rich environments (HCl ≥ 0.4 mol/L), corrosion intensifies, and corrosion products become porous, facilitating longitudinal grooves and deep pits. EIS data confirm decreased polarization resistance (e.g., R<sub>p</sub> drops from 4211 Ω·cm² to 2297 Ω·cm² in 7.5 wt% NaCl), and Warburg impedance emerges, signifying diffusion-controlled corrosion. The dominant mechanism involves electrochemical reactions where Cl⁻ and H⁺ act in concert to aggressively promote Fe dissolution via soluble complexes (e.g., [FeCl(OH)]⁻<sub>ad</sub>), while acidic conditions inhibit passivation. These findings highlight the critical vulnerability of DH36 steel in aggressive marine settings, providing essential insights for enhancing corrosion resistance in offshore structures.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101230"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682364","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 work investigates the reaction kinetics in a highly concentrated (×50) mixture of calcium sulfate (CaSO₄) and sodium fluoride (NaF) using real-time, in-situ Electrochemical Impedance Spectroscopy (EIS) over 48 h. The primary objective was to establish the electrochemical profile and monitor ion transport dynamics under aggressive, non-equilibrium conditions designed to accelerate precipitation kinetics. Analysis of the complex conductivity spectra (σ′ and σ′′) and Nyquist plots, modeled with an equivalent electrical circuit R₁(R₂//CPE), revealed two distinct kinetic regimes. The temporal evolution of the dc conductivity (σ₀) showed an initial decrease, followed by a rise, culminating in stabilization after approximately 19 h. This stabilization is interpreted as the establishment of a dynamic equilibrium state. Concurrent trends in the high-frequency conductivity (σ∞), CPE exponent (p), and relaxation time (τ) suggest significant microstructural evolution within the system. While the electrochemical data are consistent with the expected precipitation of CaF₂ and provide a kinetic profile suggesting a potentially faster route to equilibrium than traditional methods, this study focuses on establishing EIS as a monitoring tool. Direct analytical confirmation of the solid phase and quantitative yield analysis are recognized as essential next steps and are the focus of immediate future work.
{"title":"Time-resolved electrochemical impedance spectroscopy study of calcium fluoride formation and ion transport dynamics in highly concentrated CaSO₄–NaF systems","authors":"Meryem Bensemlali , Halima Mortadi , Abdellatif Aarfane , Abdoullatif Baraket , Abdelowahed Hajjaji , Fouad Belhora , Mina Bakasse , Najoua Labjar , Said Laasri , Hamid Nasrellah","doi":"10.1016/j.ijoes.2025.101249","DOIUrl":"10.1016/j.ijoes.2025.101249","url":null,"abstract":"<div><div>This work investigates the reaction kinetics in a highly concentrated (×50) mixture of calcium sulfate (CaSO₄) and sodium fluoride (NaF) using real-time, in-situ Electrochemical Impedance Spectroscopy (EIS) over 48 h. The primary objective was to establish the electrochemical profile and monitor ion transport dynamics under aggressive, non-equilibrium conditions designed to accelerate precipitation kinetics. Analysis of the complex conductivity spectra (σ′ and σ′′) and Nyquist plots, modeled with an equivalent electrical circuit R₁(R₂//CPE), revealed two distinct kinetic regimes. The temporal evolution of the dc conductivity (σ₀) showed an initial decrease, followed by a rise, culminating in stabilization after approximately 19 h. This stabilization is interpreted as the establishment of a dynamic equilibrium state. Concurrent trends in the high-frequency conductivity (σ∞), CPE exponent (p), and relaxation time (τ) suggest significant microstructural evolution within the system. While the electrochemical data are consistent with the expected precipitation of CaF₂ and provide a kinetic profile suggesting a potentially faster route to equilibrium than traditional methods, this study focuses on establishing EIS as a monitoring tool. Direct analytical confirmation of the solid phase and quantitative yield analysis are recognized as essential next steps and are the focus of immediate future work.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101249"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733572","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 : 2026-01-01Epub Date: 2025-11-26DOI: 10.1016/j.ijoes.2025.101254
Kusuma D. , Raghavendra S.C. , Revanasiddappa M. , Raghavendra N.
The development of sustainable humidity sensors is crucial for next-generation electronics and telecommunication systems. In this study, silver-coated polypyrrole (Ag–PPy) nanocomposites integrated with indium oxide (In₂O₃, 2–10 wt%) were synthesized via a green route using phytochemical-rich green tea extract as a natural reducing and stabilizing agent. This eco-friendly approach enabled controlled nanoparticle formation while minimizing hazardous by-products. Comprehensive structural and morphological characterization confirmed the successful fabrication of hybrid nanocomposites with tunable physicochemical properties. Humidity-sensing investigations revealed that increasing In₂O₃ content enhanced baseline resistance and sensitivity. Composites containing 6 % and 10 % In₂O₃ exhibited sharp decreases in resistance with increasing relative humidity, demonstrating superior sensitivity, whereas the 2 % composite provided a stable, reversible response, ensuring reliable operation. The improved sensing performance arises from the synergistic effects of the conductive PPy framework, plasmonic Ag, and semiconducting In₂O₃, which collectively facilitate charge transport and water adsorption. These findings highlight Ag–PPy/In₂O₃ nanocomposites as promising eco-engineered materials for humidity sensing in flexible electronics, environmental monitoring, and smart communication technologies.
{"title":"Silver-coated polypyrrole/indium oxide (Ag-PPY/In₂O₃) nanocomposites for humidity sensing","authors":"Kusuma D. , Raghavendra S.C. , Revanasiddappa M. , Raghavendra N.","doi":"10.1016/j.ijoes.2025.101254","DOIUrl":"10.1016/j.ijoes.2025.101254","url":null,"abstract":"<div><div>The development of sustainable humidity sensors is crucial for next-generation electronics and telecommunication systems. In this study, silver-coated polypyrrole (Ag–PPy) nanocomposites integrated with indium oxide (In₂O₃, 2–10 wt%) were synthesized via a green route using phytochemical-rich green tea extract as a natural reducing and stabilizing agent. This eco-friendly approach enabled controlled nanoparticle formation while minimizing hazardous by-products. Comprehensive structural and morphological characterization confirmed the successful fabrication of hybrid nanocomposites with tunable physicochemical properties. Humidity-sensing investigations revealed that increasing In₂O₃ content enhanced baseline resistance and sensitivity. Composites containing 6 % and 10 % In₂O₃ exhibited sharp decreases in resistance with increasing relative humidity, demonstrating superior sensitivity, whereas the 2 % composite provided a stable, reversible response, ensuring reliable operation. The improved sensing performance arises from the synergistic effects of the conductive PPy framework, plasmonic Ag, and semiconducting In₂O₃, which collectively facilitate charge transport and water adsorption. These findings highlight Ag–PPy/In₂O₃ nanocomposites as promising eco-engineered materials for humidity sensing in flexible electronics, environmental monitoring, and smart communication technologies.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101254"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616611","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 : 2026-01-01Epub Date: 2025-11-27DOI: 10.1016/j.ijoes.2025.101253
A. Parrales , Sung-Hyuk Cha , J.M. Angeles , D.E. Millán-Ocampo , R. López-Sesenes , J.A. Hernández
In this study, artificial neural networks were proposed and applied to estimate the noise resistance () of the AA2024–AZ31 alloy exposed to 0.05 M NaCl with 0, 2, 4, 6, 8, and 10 mM of cerium(III) nitrate hexahydrate. Three pseudo-random number generators (MCG16807, MLF6331, and Mersenne Twister), two preprocessing strategies (normalization and standardization), and several transfer functions were evaluated to determine their impact on predictive accuracy. The Mersenne Twister method, combined with standardization, produced the most consistent results. The best performance was achieved with the dSiLU transfer function and seven neurons with a determination correlation () of 0.998 and an RMSE of 33.363. Meanwhile, the Sinc-Squared function yielded results comparable to the best model.
在本研究中，提出了人工神经网络并应用于AA2024-AZ31合金在0.05 M NaCl和0、2、4、6、8和10 mM六水硝酸铈（III）下的抗噪声性能（Rn）的估算。评估了三种伪随机数生成器（MCG16807、MLF6331和Mersenne Twister）、两种预处理策略（归一化和标准化）以及几种传递函数对预测精度的影响。梅森扭扭法与标准化相结合，产生了最一致的结果。dSiLU传递函数与7个神经元的相关性（R2）为0.998，RMSE为33.363。同时，sinc2 ^ 2函数得到的结果与最佳模型相当。
{"title":"Artificial neural network modeling of electrochemical noise for predicting corrosion resistance of AA2024-AZ31 alloy in chloride solutions with cerium(III) nitrate hexahydrate","authors":"A. Parrales , Sung-Hyuk Cha , J.M. Angeles , D.E. Millán-Ocampo , R. López-Sesenes , J.A. Hernández","doi":"10.1016/j.ijoes.2025.101253","DOIUrl":"10.1016/j.ijoes.2025.101253","url":null,"abstract":"<div><div>In this study, artificial neural networks were proposed and applied to estimate the noise resistance (<span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>) of the AA2024–AZ31 alloy exposed to 0.05 M NaCl with 0, 2, 4, 6, 8, and 10 mM of cerium(III) nitrate hexahydrate. Three pseudo-random number generators (MCG16807, MLF6331, and Mersenne Twister), two preprocessing strategies (normalization and standardization), and several transfer functions were evaluated to determine their impact on predictive accuracy. The Mersenne Twister method, combined with standardization, produced the most consistent results. The best performance was achieved with the dSiLU transfer function and seven neurons with a determination correlation (<span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>) of 0.998 and an RMSE of 33.363. Meanwhile, the Sinc-Squared function yielded results comparable to the best model.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101253"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682366","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 : 2026-01-01Epub Date: 2025-12-05DOI: 10.1016/j.ijoes.2025.101262
Keqiang Ding , Xiaoxuan Liang , Ying Bai , Yiqing Chen , Jiawen Bao , Qian Zhao , Mengqing Niu , Wanting Shi , Hui Wang
<div><div>For the first time, a novel kind of alkaline hydrogen evolution reaction (HER) catalyst, namely, a flaky graphite (denoted as FG) and nickelous oxide (NiO) composite material supported platinum (Pt) catalyst (denoted as Pt/FG-NiO), is prepared via an air calcination-assisted hydrothermal method, in which the commercial graphite, one kind of nickel-containing substance (nickel acetate tetrahydrate (Ni(CH<sub>3</sub>COO)<sub>2</sub>·4 H<sub>2</sub>O) or nickel acetylacetonate (C<sub>10</sub>H<sub>14</sub>NiO<sub>4</sub>) or nickel oxalate dehydrate (NiC<sub>2</sub>O<sub>4</sub>·2 H<sub>2</sub>O)) and chloroplatinic acid hexahydrate (H<sub>2</sub>PtCl<sub>6</sub>·6 H<sub>2</sub>O) are utilized as the starting materials. In this work, firstly, three precursors are synthesized through calcining the mixture having the commercial graphite and one kind of nickel-containing substance in air at 550℃ for 1 h, namely, precursor p<sub>1</sub>, p<sub>2</sub> and p<sub>3</sub> are respectively prepared using Ni(CH<sub>3</sub>COO)<sub>2</sub>·4 H<sub>2</sub>O, C<sub>10</sub>H<sub>14</sub>NiO<sub>4</sub> and NiC<sub>2</sub>O<sub>4</sub>·2 H<sub>2</sub>O. Subsequently, the resulting precursor p<sub>1</sub>, p<sub>2</sub> and p<sub>3</sub> are subjected to the hydrothermal treatment in the presence of chloroplatinic acid solution, respectively, generating catalyst c<sub>1</sub>, c<sub>2</sub> and c<sub>3</sub>. As demonstrated by XRD and XPS results, graphite, NiO and metallic Pt are the major substances of all fabricated catalysts. More importantly, all prepared catalysts, especially catalyst c<sub>1</sub>, showed an excellent electrocatalytic activity towards alkaline HER. For example, the overpotential value to attain a HER current density of 10 mA cm<sup>−2</sup> on catalyst c<sub>1</sub> is as lower as 39.6 mV, being rather lower than that of catalyst c<sub>2</sub> (52.2 mV) and c<sub>3</sub> (57.2 mV). To be noted, the value of 39.6 mV for catalyst c<sub>1</sub> is very close to that of the commercial platinum/carbon (Pt/C) catalyst (37.9 mV). The Tafel slope values of catalyst c<sub>1</sub>, c<sub>2</sub>, c<sub>3</sub> and Pt/C for HER are about 41.3, 52.4, 59.0 and 49.5 mV dec<sup>−1</sup>, respectively. In the chronoamperometry (CA) test, the HER current density measured on catalyst c<sub>1</sub> is about 7.81 mA cm<sup>−2</sup> after 10 h, being much higher than that of catalyst c<sub>2</sub> (2.15 mA cm<sup>−2</sup>), c<sub>3</sub> (2.73 mA cm<sup>−2</sup>) and the commercial Pt/C (5.63 mA cm<sup>−2</sup>). After a thorough characterization, the greatly decreased R<sub>ct</sub> and the larger ECSA value are analyzed to be the main reasons giving catalyst c<sub>1</sub> an outstanding HER electrocatalytic activity. Showing the preparation of a novel HER catalyst of Pt/FG-NiO as well as its satisfied HER electrocatalytic performance are the main contributions of the present work, which is very beneficial to the development of Ni and Pt based alka
{"title":"Pt/flaky graphite–NiO composite electrocatalyst for the alkaline hydrogen evolution reaction","authors":"Keqiang Ding , Xiaoxuan Liang , Ying Bai , Yiqing Chen , Jiawen Bao , Qian Zhao , Mengqing Niu , Wanting Shi , Hui Wang","doi":"10.1016/j.ijoes.2025.101262","DOIUrl":"10.1016/j.ijoes.2025.101262","url":null,"abstract":"<div><div>For the first time, a novel kind of alkaline hydrogen evolution reaction (HER) catalyst, namely, a flaky graphite (denoted as FG) and nickelous oxide (NiO) composite material supported platinum (Pt) catalyst (denoted as Pt/FG-NiO), is prepared via an air calcination-assisted hydrothermal method, in which the commercial graphite, one kind of nickel-containing substance (nickel acetate tetrahydrate (Ni(CH<sub>3</sub>COO)<sub>2</sub>·4 H<sub>2</sub>O) or nickel acetylacetonate (C<sub>10</sub>H<sub>14</sub>NiO<sub>4</sub>) or nickel oxalate dehydrate (NiC<sub>2</sub>O<sub>4</sub>·2 H<sub>2</sub>O)) and chloroplatinic acid hexahydrate (H<sub>2</sub>PtCl<sub>6</sub>·6 H<sub>2</sub>O) are utilized as the starting materials. In this work, firstly, three precursors are synthesized through calcining the mixture having the commercial graphite and one kind of nickel-containing substance in air at 550℃ for 1 h, namely, precursor p<sub>1</sub>, p<sub>2</sub> and p<sub>3</sub> are respectively prepared using Ni(CH<sub>3</sub>COO)<sub>2</sub>·4 H<sub>2</sub>O, C<sub>10</sub>H<sub>14</sub>NiO<sub>4</sub> and NiC<sub>2</sub>O<sub>4</sub>·2 H<sub>2</sub>O. Subsequently, the resulting precursor p<sub>1</sub>, p<sub>2</sub> and p<sub>3</sub> are subjected to the hydrothermal treatment in the presence of chloroplatinic acid solution, respectively, generating catalyst c<sub>1</sub>, c<sub>2</sub> and c<sub>3</sub>. As demonstrated by XRD and XPS results, graphite, NiO and metallic Pt are the major substances of all fabricated catalysts. More importantly, all prepared catalysts, especially catalyst c<sub>1</sub>, showed an excellent electrocatalytic activity towards alkaline HER. For example, the overpotential value to attain a HER current density of 10 mA cm<sup>−2</sup> on catalyst c<sub>1</sub> is as lower as 39.6 mV, being rather lower than that of catalyst c<sub>2</sub> (52.2 mV) and c<sub>3</sub> (57.2 mV). To be noted, the value of 39.6 mV for catalyst c<sub>1</sub> is very close to that of the commercial platinum/carbon (Pt/C) catalyst (37.9 mV). The Tafel slope values of catalyst c<sub>1</sub>, c<sub>2</sub>, c<sub>3</sub> and Pt/C for HER are about 41.3, 52.4, 59.0 and 49.5 mV dec<sup>−1</sup>, respectively. In the chronoamperometry (CA) test, the HER current density measured on catalyst c<sub>1</sub> is about 7.81 mA cm<sup>−2</sup> after 10 h, being much higher than that of catalyst c<sub>2</sub> (2.15 mA cm<sup>−2</sup>), c<sub>3</sub> (2.73 mA cm<sup>−2</sup>) and the commercial Pt/C (5.63 mA cm<sup>−2</sup>). After a thorough characterization, the greatly decreased R<sub>ct</sub> and the larger ECSA value are analyzed to be the main reasons giving catalyst c<sub>1</sub> an outstanding HER electrocatalytic activity. Showing the preparation of a novel HER catalyst of Pt/FG-NiO as well as its satisfied HER electrocatalytic performance are the main contributions of the present work, which is very beneficial to the development of Ni and Pt based alka","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101262"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786960","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 : 2026-01-01Epub Date: 2025-11-19DOI: 10.1016/j.ijoes.2025.101242
Ananya S. Agnihotri, M. Nidhin
In this study, we present a highly selective and sensitive electrochemical sensor for the detection of Amlodipine besylate (AMP) using α-Fe2O3 nanoparticles (IO) functionalized with alanine (IOALA) to enhance electrochemical activity. The IO nanoparticles were synthesized through a starch-assisted template method and then modified with alanine, improving their stability and reducing agglomerate size. Comprehensive characterization of IOALA was conducted using XRD, FTIR, DLS, VSM, FESEM-EDX, HRTEM, and SAED, confirming the structural integrity and functionalization of the nanomaterial. The IOALA was subsequently immobilized on a glassy carbon electrode (GCE) to fabricate the IOALA/GCE sensor, where electrochemical parameters, including scan rate, electrolyte pH, and AMP concentration, were meticulously optimized. Differential pulse voltammetry (DPV) was employed to achieve precise quantification of AMP, revealing a remarkable detection limit of 1.29 nM and a broad linear dynamic range of 3.89 nM to 500.03 nM. The sensor demonstrated excellent reproducibility and selectivity, exhibiting high resistance to interference, making it reliable for real-sample analysis. Practical application was validated by detecting AMP in generic drug formulations, highlighting the sensor's potential for real-world pharmaceutical monitoring. This novel IOALA/GCE platform offers an efficient, cost-effective, and robust approach for AMP detection, contributing to the advancement of electrochemical sensors in pharmaceutical analysis.
{"title":"Highly sensitive and selective electrochemical detection of amlodipine besylate using β-alanine-modified α-Fe₂O₃ nanoparticles","authors":"Ananya S. Agnihotri, M. Nidhin","doi":"10.1016/j.ijoes.2025.101242","DOIUrl":"10.1016/j.ijoes.2025.101242","url":null,"abstract":"<div><div>In this study, we present a highly selective and sensitive electrochemical sensor for the detection of Amlodipine besylate (AMP) using α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles (IO) functionalized with alanine (IOALA) to enhance electrochemical activity. The IO nanoparticles were synthesized through a starch-assisted template method and then modified with alanine, improving their stability and reducing agglomerate size. Comprehensive characterization of IOALA was conducted using XRD, FTIR, DLS, VSM, FESEM-EDX, HRTEM, and SAED, confirming the structural integrity and functionalization of the nanomaterial. The IOALA was subsequently immobilized on a glassy carbon electrode (GCE) to fabricate the IOALA/GCE sensor, where electrochemical parameters, including scan rate, electrolyte pH, and AMP concentration, were meticulously optimized. Differential pulse voltammetry (DPV) was employed to achieve precise quantification of AMP, revealing a remarkable detection limit of 1.29 nM and a broad linear dynamic range of 3.89 nM to 500.03 nM. The sensor demonstrated excellent reproducibility and selectivity, exhibiting high resistance to interference, making it reliable for real-sample analysis. Practical application was validated by detecting AMP in generic drug formulations, highlighting the sensor's potential for real-world pharmaceutical monitoring. This novel IOALA/GCE platform offers an efficient, cost-effective, and robust approach for AMP detection, contributing to the advancement of electrochemical sensors in pharmaceutical analysis.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101242"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571100","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 : 2026-01-01Epub Date: 2025-11-27DOI: 10.1016/j.ijoes.2025.101258
Zeyu Zuo , Zhenhua Yu , Ying Yan , Jie Zhang , Ke Wang , Xilei Chen , Ruiyong Zhang , Qian An
This study investigates the effects of different cathodic protection potentials on SRB adhesion and corrosion product formation in marine sediment containing sulfate-reducing bacteria (SRB), using weight loss measurements, surface morphology analysis, corrosion product characterization, and electrochemical testing. The results show that SRB form biofilms on the cathodic surface, which promote the formation of corrosion films. These films provide a certain degree of protection to the metal, and their composition changes with the applied potential. The efficiency of cathodic protection is jointly influenced by the protection potential and SRB activity. The study demonstrates that appropriately shifting the cathodic protection potential in the negative direction can suppress SRB activity while utilizing its role in promoting corrosion film formation, thereby enhancing protection performance. In actual marine environments, a suitably negative cathodic protection potential can both inhibit SRB and improve protection efficiency by facilitating corrosion film formation.
{"title":"Influence of cathodic protection potential on the efficiency of steel protection in marine sediments containing sulfate-reducing bacteria","authors":"Zeyu Zuo , Zhenhua Yu , Ying Yan , Jie Zhang , Ke Wang , Xilei Chen , Ruiyong Zhang , Qian An","doi":"10.1016/j.ijoes.2025.101258","DOIUrl":"10.1016/j.ijoes.2025.101258","url":null,"abstract":"<div><div>This study investigates the effects of different cathodic protection potentials on SRB adhesion and corrosion product formation in marine sediment containing sulfate-reducing bacteria (SRB), using weight loss measurements, surface morphology analysis, corrosion product characterization, and electrochemical testing. The results show that SRB form biofilms on the cathodic surface, which promote the formation of corrosion films. These films provide a certain degree of protection to the metal, and their composition changes with the applied potential. The efficiency of cathodic protection is jointly influenced by the protection potential and SRB activity. The study demonstrates that appropriately shifting the cathodic protection potential in the negative direction can suppress SRB activity while utilizing its role in promoting corrosion film formation, thereby enhancing protection performance. In actual marine environments, a suitably negative cathodic protection potential can both inhibit SRB and improve protection efficiency by facilitating corrosion film formation.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101258"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733573","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 : 2026-01-01Epub Date: 2025-12-02DOI: 10.1016/j.ijoes.2025.101260
Ajayb Saud Alresheedi , Manal El Sayed
Uniformity of metal deposition is crucial in electrodeposition processes since it directly influences coating performance, corrosion resistance, and mechanical durability, especially for components with complex geometries. This study evaluates and compares the throwing power (TP) and throwing index (TI) of three commonly used zinc electroplating baths —chloride, sulphate, and acetate- under controlled conditions. A Haring-Blum cell was used for TP measurements, and TI values were calculated from metal distribution ratios across different cathode distances. Potentiodynamic cathodic polarization curves were also recorded to help correlate electrochemical behavior with deposition uniformity. The zinc chloride bath consistently demonstrated superior TP (14.28 – 60.0) and TI (1.33–4.0) across a wide range of zinc salt concentrations, current densities, and pH values, owing to its higher conductivity and enhanced polarization behavior. Sulphate-based baths exhibited moderate TP (5.26–33.33) and TI (1.0–2.32) with significant sensitivity to operating conditions, whereas acetate-based baths exhibited the lowest TP (5.26–14.28) and TI (1.0–1.66), most likely due to limited ion mobility and conductivity. Microstructural and surface characterization confirmed these findings, with the chloride bath exhibiting the most balanced performance in terms of hardness, morphology, and coating uniformity. These results lay the groundwork for improving zinc-electroplating baths to achieve better coating longevity, corrosion resistance, and dependable performance in industrial applications that demand high surface coverage and exact thickness control.
{"title":"Evaluation and comparison of throwing power in zinc electroplating baths","authors":"Ajayb Saud Alresheedi , Manal El Sayed","doi":"10.1016/j.ijoes.2025.101260","DOIUrl":"10.1016/j.ijoes.2025.101260","url":null,"abstract":"<div><div>Uniformity of metal deposition is crucial in electrodeposition processes since it directly influences coating performance, corrosion resistance, and mechanical durability, especially for components with complex geometries. This study evaluates and compares the throwing power (TP) and throwing index (TI) of three commonly used zinc electroplating baths —chloride, sulphate, and acetate- under controlled conditions. A Haring-Blum cell was used for TP measurements, and TI values were calculated from metal distribution ratios across different cathode distances. Potentiodynamic cathodic polarization curves were also recorded to help correlate electrochemical behavior with deposition uniformity. The zinc chloride bath consistently demonstrated superior TP (14.28 – 60.0) and TI (1.33–4.0) across a wide range of zinc salt concentrations, current densities, and pH values, owing to its higher conductivity and enhanced polarization behavior. Sulphate-based baths exhibited moderate TP (5.26–33.33) and TI (1.0–2.32) with significant sensitivity to operating conditions, whereas acetate-based baths exhibited the lowest TP (5.26–14.28) and TI (1.0–1.66), most likely due to limited ion mobility and conductivity. Microstructural and surface characterization confirmed these findings, with the chloride bath exhibiting the most balanced performance in terms of hardness, morphology, and coating uniformity. These results lay the groundwork for improving zinc-electroplating baths to achieve better coating longevity, corrosion resistance, and dependable performance in industrial applications that demand high surface coverage and exact thickness control.</div></div>","PeriodicalId":13872,"journal":{"name":"International Journal of Electrochemical Science","volume":"21 1","pages":"Article 101260"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682010","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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