Deependra Jhankal, Mohammed Saquib Khan, Krishna K. Jhankal, Kanupriya Sachdev
The design and development of an alternative counter electrode (CE) using graphene-based low-cost material for the dye-sensitized solar cell (DSSC) is the major motivation of the current research to replace the traditional platinum counter electrode. Herein, we prepared reduced graphene oxide (rGO) and investigated it for an efficient CE in DSSC. The structural and morphological properties of rGO are analyzed using FESEM, TEM and Raman techniques. The performance of I3- reduction on the CE is characterized by the EIS Nyquist plot, cyclic voltammetry, and the Tafel curve. The measured electrochemical results suggested that rGO CE has a lower charge transfer resistance (Rct), higher cathodic current density (Jrd), and higher Tafel slope as compared to graphene oxide (GO) CE, revealing that rGO CE has good catalytic activity towards the I3- reduction.
{"title":"Electrochemical evaluations of reduced graphene oxide for efficient counter electrode in dye-sensitized solar cell","authors":"Deependra Jhankal, Mohammed Saquib Khan, Krishna K. Jhankal, Kanupriya Sachdev","doi":"10.5599/jese.1977","DOIUrl":"https://doi.org/10.5599/jese.1977","url":null,"abstract":"The design and development of an alternative counter electrode (CE) using graphene-based low-cost material for the dye-sensitized solar cell (DSSC) is the major motivation of the current research to replace the traditional platinum counter electrode. Herein, we prepared reduced graphene oxide (rGO) and investigated it for an efficient CE in DSSC. The structural and morphological properties of rGO are analyzed using FESEM, TEM and Raman techniques. The performance of I3- reduction on the CE is characterized by the EIS Nyquist plot, cyclic voltammetry, and the Tafel curve. The measured electrochemical results suggested that rGO CE has a lower charge transfer resistance (Rct), higher cathodic current density (Jrd), and higher Tafel slope as compared to graphene oxide (GO) CE, revealing that rGO CE has good catalytic activity towards the I3- reduction.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135192643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kasem K. Kasem, Mattie Tom, Mehreen Tahir, Logan Cox
Inorganic/organic interface assemblies were created from poly 3,4-ethylenedioxythiophene (PEDOT) interfaced with amorphous BiVO4 and with BiVO4-TiO2. Electrochemical cells-based thermoplastic gel electrolytes containing KI/I2 were used to study the photoelectrochemical behavior of the Inorganic/organic interface electrodes. Optical studies show that doping BiVO4 with TiO2 narrowed the optical band gap to allow more absorption in the visible region and increases solar energy conversion. Evidence for both direct and indirect band gaps was observed. Refractive index data indicates that BiVO4 and BiVO4/TiO2 obey the anomalous dispassion multiple-oscillator model. Chronoamperometry of these assemblies shows the phenomena of dark current, which correlates to the presence of random electron/hole generation in the depletion layer. PEDOT enhances the photoactivity of BiVO4 only. Electrochemical impedance spectroscopy studies indicated that both kinetic and diffusional control at high and low frequencies, respectively. Furthermore, studies show that as frequency increases, the conductivity increases due to dispersion and charge carrier hopping. All photoactivity outcomes were reproducible.
{"title":"Electrochemical and optical studies on photoactive BiVO4-TiO2/poly 3,4-ethylenedioxythiophene assemblies in gel electrolyte: Role of inorganic/organic interfaces in surface functionalization","authors":"Kasem K. Kasem, Mattie Tom, Mehreen Tahir, Logan Cox","doi":"10.5599/jese.1951","DOIUrl":"https://doi.org/10.5599/jese.1951","url":null,"abstract":"Inorganic/organic interface assemblies were created from poly 3,4-ethylenedioxythiophene (PEDOT) interfaced with amorphous BiVO4 and with BiVO4-TiO2. Electrochemical cells-based thermoplastic gel electrolytes containing KI/I2 were used to study the photoelectrochemical behavior of the Inorganic/organic interface electrodes. Optical studies show that doping BiVO4 with TiO2 narrowed the optical band gap to allow more absorption in the visible region and increases solar energy conversion. Evidence for both direct and indirect band gaps was observed. Refractive index data indicates that BiVO4 and BiVO4/TiO2 obey the anomalous dispassion multiple-oscillator model. Chronoamperometry of these assemblies shows the phenomena of dark current, which correlates to the presence of random electron/hole generation in the depletion layer. PEDOT enhances the photoactivity of BiVO4 only. Electrochemical impedance spectroscopy studies indicated that both kinetic and diffusional control at high and low frequencies, respectively. Furthermore, studies show that as frequency increases, the conductivity increases due to dispersion and charge carrier hopping. All photoactivity outcomes were reproducible.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135059269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A major challenge of Li metal electrodes is the growth of high surface area lithium during Li deposition with a variety of possible shapes and growing mechanisms. They are reactive and lead to active lithium losses, electrolyte depletion and safety concerns due to a potential risk of short-circuits and thermal runaway. This work focuses on the mechanism of tip-growing Li dendrite as a particular high surface area lithium morphology. Its formation mechanism is well-known and is triggered during concentration polarization, i.e. during mass (Li+) transport limitations, which has been thoroughly investigated in literature with liquid electrolytes. This work aims to give a stimulating perspective on this formation mechanism by considering solid polymer electrolytes. The in-here shown absence of the characteristic “voltage noise” immediately after complete concentration polarization, being an indicator for tip-growing dendritic growth, rules out the occurrence of the particular tip-growing morphology for solid polymer electrolytes under the specific electrochemical conditions. The generally poorer kinetics of solid polymer electrolytes compared to liquid electrolytes imply lower limiting currents, i.e. lower currents to realize complete concentration polarization. Hence, this longer-lasting Li-deposition times in solid polymer electrolytes are assumed to prevent tip-growing mechanism via timely enabling solid electrolyte interphase formation on fresh Li deposits, while, as stated in previous literature, in liquid electrolytes, Li dendrite tip-growth process is faster than solid electrolyte interphase formation kinetics. It can be reasonably concluded that tip-growing Li dendrites are in general practically unlikely for both, (i) the lower conducting electrolytes like solid polymer electrolytes due to enabling solid electrolyte interphase formation and (ii) good-conducting electrolytes like liquids due to an impractically high current required for concentration polarization.
{"title":"Perspective on the mechanism of mass transport-induced (tip-growing) Li dendrite formation by comparing conventional liquid organic solvent with solid polymer-based electrolytes","authors":"L. Stolz, M. Winter, J. Kasnatscheew","doi":"10.5599/jese.1724","DOIUrl":"https://doi.org/10.5599/jese.1724","url":null,"abstract":"A major challenge of Li metal electrodes is the growth of high surface area lithium during Li deposition with a variety of possible shapes and growing mechanisms. They are reactive and lead to active lithium losses, electrolyte depletion and safety concerns due to a potential risk of short-circuits and thermal runaway. This work focuses on the mechanism of tip-growing Li dendrite as a particular high surface area lithium morphology. Its formation mechanism is well-known and is triggered during concentration polarization, i.e. during mass (Li+) transport limitations, which has been thoroughly investigated in literature with liquid electrolytes. This work aims to give a stimulating perspective on this formation mechanism by considering solid polymer electrolytes. The in-here shown absence of the characteristic “voltage noise” immediately after complete concentration polarization, being an indicator for tip-growing dendritic growth, rules out the occurrence of the particular tip-growing morphology for solid polymer electrolytes under the specific electrochemical conditions. The generally poorer kinetics of solid polymer electrolytes compared to liquid electrolytes imply lower limiting currents, i.e. lower currents to realize complete concentration polarization. Hence, this longer-lasting Li-deposition times in solid polymer electrolytes are assumed to prevent tip-growing mechanism via timely enabling solid electrolyte interphase formation on fresh Li deposits, while, as stated in previous literature, in liquid electrolytes, Li dendrite tip-growth process is faster than solid electrolyte interphase formation kinetics. It can be reasonably concluded that tip-growing Li dendrites are in general practically unlikely for both, (i) the lower conducting electrolytes like solid polymer electrolytes due to enabling solid electrolyte interphase formation and (ii) good-conducting electrolytes like liquids due to an impractically high current required for concentration polarization.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"26 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80978211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
After a one-year delay caused by the COVID-19 pandemic, the 8th Regional Symposium on Electrochemistry of South-East Europe was held jointly with the 9th Kurt Schwabe Symposium from July 11-15, 2022 at Graz University of Technology in Austria. This special edition of the jESE contains a collection of articles presented at this meeting. The 5-day event (including Monday’s Satellite Student Symposium) organized by the Association of South-East European Electrochemists (ASEEE) featured 5 plenaries, 15 keynotes, 71 contributed talks and 38 posters and was attended by 152 scientists and researchers from 23 countries.
{"title":"Joint event: 8th Regional Symposium on Electrochemistry of South-East Europe (RSE-SEE 8) and 9th Kurt Schwabe Symposium","authors":"B. Gollas, V. Hacker","doi":"10.5599/jese.1989","DOIUrl":"https://doi.org/10.5599/jese.1989","url":null,"abstract":"After a one-year delay caused by the COVID-19 pandemic, the 8th Regional Symposium on Electrochemistry of South-East Europe was held jointly with the 9th Kurt Schwabe Symposium from July 11-15, 2022 at Graz University of Technology in Austria. This special edition of the jESE contains a collection of articles presented at this meeting. The 5-day event (including Monday’s Satellite Student Symposium) organized by the Association of South-East European Electrochemists (ASEEE) featured 5 plenaries, 15 keynotes, 71 contributed talks and 38 posters and was attended by 152 scientists and researchers from 23 countries.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"14 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86209356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of copper as a material in various fields is widely recognized. However, in acidic environments, the electrical and mechanical properties of copper undergo negative alterations, resulting in its dissolution. To protect copper from degradation, the most effective approach is to employ inhibitors. Hence, in this paper, the expired ibuprofen drug has been investigated as a corrosion inhibitor for copper in 0.5 M H2SO4, employing weight loss and electrochemical tests. Compared with the pharmaceutical products used by other researchers in this field, the results showed that ibuprofen is highly effective in protecting copper from corrosion. It was noted that the inhibitory efficacy of ibuprofen increases with concentration. In addition, it was found that its adsorption follows Langmuir isotherm.
铜作为一种材料在各个领域的应用得到了广泛的认可。然而，在酸性环境中，铜的电学和机械性能发生负面变化，导致其溶解。为了防止铜的降解，最有效的方法是使用抑制剂。因此，本文采用失重和电化学试验的方法，研究了过期布洛芬药物在0.5 M H2SO4中作为铜的缓蚀剂。与其他研究人员在该领域使用的药物产品进行比较，结果表明，布洛芬对铜的防腐作用非常有效。注意到布洛芬的抑制效果随浓度增加而增加。此外，还发现其吸附遵循Langmuir等温线。
{"title":"Corrosion inhibition effect of expired ibuprofen drug on copper in sulfuric acid solution","authors":"Said El Harrari, S. Ayoub, D. Takky, Y. Naimi","doi":"10.5599/jese.1867","DOIUrl":"https://doi.org/10.5599/jese.1867","url":null,"abstract":"The application of copper as a material in various fields is widely recognized. However, in acidic environments, the electrical and mechanical properties of copper undergo negative alterations, resulting in its dissolution. To protect copper from degradation, the most effective approach is to employ inhibitors. Hence, in this paper, the expired ibuprofen drug has been investigated as a corrosion inhibitor for copper in 0.5 M H2SO4, employing weight loss and electrochemical tests. Compared with the pharmaceutical products used by other researchers in this field, the results showed that ibuprofen is highly effective in protecting copper from corrosion. It was noted that the inhibitory efficacy of ibuprofen increases with concentration. In addition, it was found that its adsorption follows Langmuir isotherm.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"45 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73800653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irfan Liaquat, A. Ziya, Athar Ibrahim, Urva Malik, Gao Qilong, Muhammad Danial
The electrochemical behaviour of alloys (Au50-Ag25-Pd25 and Ni88.6-Cr11.4) was studied in Fusayama's artificial saliva at pH 6.5 and 37 °C by using open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization measurements. Electrochemical impedance spectroscopy results were simulated with an equivalent electrical circuit. After immersion in artificial saliva, surface characterization of samples was done using scanning electron microscopy connected with energy-dispersive spectroscopy. All obtained results revealed that Au50-Ag25-Pd25 alloy is much more resistive than Ni88.6-Cr11.4 and can be recommended for the effective treatment of patients with dental prosthetics that have metal frameworks.s.
{"title":"Comparative corrosion behavior of Au50-Ag25-Pd25 and Ni88.6-Cr11.4 alloys utilized in dental applications","authors":"Irfan Liaquat, A. Ziya, Athar Ibrahim, Urva Malik, Gao Qilong, Muhammad Danial","doi":"10.5599/jese.1931","DOIUrl":"https://doi.org/10.5599/jese.1931","url":null,"abstract":"The electrochemical behaviour of alloys (Au50-Ag25-Pd25 and Ni88.6-Cr11.4) was studied in Fusayama's artificial saliva at pH 6.5 and 37 °C by using open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization measurements. Electrochemical impedance spectroscopy results were simulated with an equivalent electrical circuit. After immersion in artificial saliva, surface characterization of samples was done using scanning electron microscopy connected with energy-dispersive spectroscopy. All obtained results revealed that Au50-Ag25-Pd25 alloy is much more resistive than Ni88.6-Cr11.4 and can be recommended for the effective treatment of patients with dental prosthetics that have metal frameworks.\u0000s.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"1 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78591539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Fouladvari, G. Firtin, B. Kahyaoglu, L. Nobili, R. Bernasconi
In the present work the electrodeposition of zinc-nickel alloys with 15-20 wt.% nickel from non-aqueous solutions based on ethylene glycol is investigated. Potentiostatic deposition conditions are used, which are found to offer optimal coating quality and superior control over composition. In addition, ammonium chloride is evaluated as additive to partially suppress zinc incorporation into the deposit and to enhance layer quality. Layers composition, surface morphology of the deposits and their anticorrosive properties are investigated. The electrochemical characteristics of the Zn-Ni electrolytes are studied using cyclic voltammetry measurements. From the phase composition point view, X-ray diffraction results confirm that a metastable γ phase is present in the as deposited Zn-Ni alloys with nickel content 16-18 wt.%. Corrosion tests show that the barrier behaviour against corrosion of Zn-Ni films electrodeposited from the NH4Cl containing bath is superior in comparison to layers plated from an additive-free bath. The use of the additive enlarges the grains and provides a compact surface structure, which upskills the anticorrosive behaviour of the deposit.
{"title":"Electrodeposition of zinc-nickel alloys from ethylene glycol-based electrolytes in presence of additives for corrosion protection","authors":"N. Fouladvari, G. Firtin, B. Kahyaoglu, L. Nobili, R. Bernasconi","doi":"10.5599/jese.1895","DOIUrl":"https://doi.org/10.5599/jese.1895","url":null,"abstract":"In the present work the electrodeposition of zinc-nickel alloys with 15-20 wt.% nickel from non-aqueous solutions based on ethylene glycol is investigated. Potentiostatic deposition conditions are used, which are found to offer optimal coating quality and superior control over composition. In addition, ammonium chloride is evaluated as additive to partially suppress zinc incorporation into the deposit and to enhance layer quality. Layers composition, surface morphology of the deposits and their anticorrosive properties are investigated. The electrochemical characteristics of the Zn-Ni electrolytes are studied using cyclic voltammetry measurements. From the phase composition point view, X-ray diffraction results confirm that a metastable γ phase is present in the as deposited Zn-Ni alloys with nickel content 16-18 wt.%. Corrosion tests show that the barrier behaviour against corrosion of Zn-Ni films electrodeposited from the NH4Cl containing bath is superior in comparison to layers plated from an additive-free bath. The use of the additive enlarges the grains and provides a compact surface structure, which upskills the anticorrosive behaviour of the deposit.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"76 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81097003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminum matrix composites outperform traditional alloys in terms of mechanical properties and corrosion resistance. Silicon carbide is the main reinforcing material in aluminum-based composites that have developed rapidly in recent years. In this investigation, aluminum-silicon carbide composites were prepared through powder metallurgy with 10 and 20 wt.% of silicon carbide reinforcement. The influence of the SiC content, sintering temperature, and sintering time on the corrosion behavior of prepared Al-SiC composites in 0.5 M hydrochloride acid solution was assessed. The surface microstructure was characterized by scanning electron microscopy with energy dispersive analysis and X-rays. The experimental results demonstrated how the sintering parameters can affect the corrosion characteristics of sintered samples. The electrochemical analysis curves showed that when increasing the sintering temperature and sintering time, there is a possibility of self-repair of damaged passive film on the surface while further reinforcing of the composite with silicon carbide prevents penetration of chloride ions. The SEM images and EDS analysis of composite surfaces after being corroded in 0.5 M HCl revealed that increasing the sintering temperature and prolonging the sintering time reduce the pitting corrosion of composites.
铝基复合材料在机械性能和耐腐蚀性方面优于传统合金。碳化硅是近年来发展迅速的铝基复合材料中的主要增强材料。采用粉末冶金法制备了碳化硅增强量分别为10%和20%的铝硅复合材料。考察了SiC含量、烧结温度和烧结时间对制备的Al-SiC复合材料在0.5 M盐酸溶液中的腐蚀行为的影响。利用扫描电子显微镜、能谱分析和x射线对其表面微观结构进行了表征。实验结果证明了烧结参数对烧结试样腐蚀特性的影响。电化学分析曲线表明，提高烧结温度和烧结时间，表面受损的钝化膜有自我修复的可能，而进一步用碳化硅增强复合材料可以防止氯离子的渗透。复合材料在0.5 M HCl中腐蚀后的SEM图像和EDS分析表明，提高烧结温度和延长烧结时间可以降低复合材料的点蚀。
{"title":"Effect of sintering temperature and time on corrosion characteristics of aluminum matrix composites","authors":"Sahib M. Mahdi, L. Ghalib","doi":"10.5599/jese.1891","DOIUrl":"https://doi.org/10.5599/jese.1891","url":null,"abstract":"Aluminum matrix composites outperform traditional alloys in terms of mechanical properties and corrosion resistance. Silicon carbide is the main reinforcing material in aluminum-based composites that have developed rapidly in recent years. In this investigation, aluminum-silicon carbide composites were prepared through powder metallurgy with 10 and 20 wt.% of silicon carbide reinforcement. The influence of the SiC content, sintering temperature, and sintering time on the corrosion behavior of prepared Al-SiC composites in 0.5 M hydrochloride acid solution was assessed. The surface microstructure was characterized by scanning electron microscopy with energy dispersive analysis and X-rays. The experimental results demonstrated how the sintering parameters can affect the corrosion characteristics of sintered samples. The electrochemical analysis curves showed that when increasing the sintering temperature and sintering time, there is a possibility of self-repair of damaged passive film on the surface while further reinforcing of the composite with silicon carbide prevents penetration of chloride ions. The SEM images and EDS analysis of composite surfaces after being corroded in 0.5 M HCl revealed that increasing the sintering temperature and prolonging the sintering time reduce the pitting corrosion of composites.\u0000 ","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"325 ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72434296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alfredo Emmanuel Hench-Cabrera, E. Quiroga‐González
Most of the reports on electrochemical ammonia detection with copper electrodes have been performed at pH 10 or higher. However, according to phase diagrams, no reactions take place between copper and ammonia under those conditions, qualifying such detection of ammonia as indirect. This short paper deals with the detection of ammonia concentration in the micromolar range through a direct mechanism at pH 9, using a Cu-decorated microstructured Si electrode. The reaction mechanism is thoroughly studied.
{"title":"Direct electrochemical detection mechanism of ammonia in aqueous solution using Cu-decorated Si microelectrodes","authors":"Alfredo Emmanuel Hench-Cabrera, E. Quiroga‐González","doi":"10.5599/jese.1843","DOIUrl":"https://doi.org/10.5599/jese.1843","url":null,"abstract":"Most of the reports on electrochemical ammonia detection with copper electrodes have been performed at pH 10 or higher. However, according to phase diagrams, no reactions take place between copper and ammonia under those conditions, qualifying such detection of ammonia as indirect. This short paper deals with the detection of ammonia concentration in the micromolar range through a direct mechanism at pH 9, using a Cu-decorated microstructured Si electrode. The reaction mechanism is thoroughly studied.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77032508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Degradation of electrode-membrane assembly of the low-temperature hydrogen fuel cells represents one of the main obstacles in wider adoption of these clean and efficient electrochemical sources of electrical energy. Chemical degradation of proton exchange membrane is initiated by hydrogen peroxide formation, which forms in the fuel cell as a by-product to water in oxygen reduction reaction and decomposes to reactive radical species, damaging to the membrane chemical structure. Depending on the operating conditions of the fuel cell, the source of hydrogen peroxide can be either cathode, anode, or, as we argue in the paper, also the Pt particles in the membrane, which originate from the cathode catalyst dissolution, diffusion into the membrane and redeposition of Pt ions inside the membrane. In the paper we propose a mathematical model of intertwined physical processes in membrane and catalyst layer, aimed at unifying the description of hydrogen peroxide formation throughout entire membrane-electrode assembly at any fuel cell operating conditions. The model results, compared to experimental data, indicate that Pt particles inside the membrane can indeed be an important source of hydrogen peroxide in aged fuel cells. For a fresh fuel cell, numerical simulation using proposed model show that hydrogen peroxide can be formed at either cathode or anode, depending on the fuel cell operating condition, but with anode production being more prominent in standard fuel cell operating conditions.
{"title":"Elucidating mechanistic background of the origin and rates of peroxide formation in low temperature proton exchange fuel cells","authors":"A. Kregar, T. Katrašnik","doi":"10.5599/jese.1659","DOIUrl":"https://doi.org/10.5599/jese.1659","url":null,"abstract":"Degradation of electrode-membrane assembly of the low-temperature hydrogen fuel cells represents one of the main obstacles in wider adoption of these clean and efficient electrochemical sources of electrical energy. Chemical degradation of proton exchange membrane is initiated by hydrogen peroxide formation, which forms in the fuel cell as a by-product to water in oxygen reduction reaction and decomposes to reactive radical species, damaging to the membrane chemical structure. Depending on the operating conditions of the fuel cell, the source of hydrogen peroxide can be either cathode, anode, or, as we argue in the paper, also the Pt particles in the membrane, which originate from the cathode catalyst dissolution, diffusion into the membrane and redeposition of Pt ions inside the membrane. In the paper we propose a mathematical model of intertwined physical processes in membrane and catalyst layer, aimed at unifying the description of hydrogen peroxide formation throughout entire membrane-electrode assembly at any fuel cell operating conditions. The model results, compared to experimental data, indicate that Pt particles inside the membrane can indeed be an important source of hydrogen peroxide in aged fuel cells. For a fresh fuel cell, numerical simulation using proposed model show that hydrogen peroxide can be formed at either cathode or anode, depending on the fuel cell operating condition, but with anode production being more prominent in standard fuel cell operating conditions.","PeriodicalId":15660,"journal":{"name":"Journal of Electrochemical Science and Engineering","volume":"1 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82370455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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