Pub Date : 2024-10-05DOI: 10.1016/j.elecom.2024.107820
Emer B. Farrell, Gareth Redmond, Robert P. Johnson
The characterization and discrimination of chemical compounds is imperative in both academia and industry, but currently relies on expensive and/or bulky instrumentation. Herein, we demonstrate that the ion transport properties of bare quartz nanopipettes containing aprotic acetonitrile electrolyte can be used discriminate isomers based on polarization and solvation, through changes to interfacial solvent ordering at the nanopore wall. This is demonstrated by monitoring the photoinduced isomerization of spirooxazine to merocyanine using the ion-current rectification of a quartz-nanopipette containing acetonitrile electrolyte, which results in an increase in rectification ratio (RR) from 3.6 ± 0.3 to 5.1 ± 0.2. This change is comparable to traditional UV–Vis absorbance and fluorescence measurements of the same process, with the appearance of a small shoulder-like absorbance peak from 400 to 500 nm, and a strong fluorescence signal at 430 nm.
{"title":"Monitoring spirooxazine–merocyanine photoisomerization with ion-current rectifying quartz nanopipettes","authors":"Emer B. Farrell, Gareth Redmond, Robert P. Johnson","doi":"10.1016/j.elecom.2024.107820","DOIUrl":"10.1016/j.elecom.2024.107820","url":null,"abstract":"<div><div>The characterization and discrimination of chemical compounds is imperative in both academia and industry, but currently relies on expensive and/or bulky instrumentation. Herein, we demonstrate that the ion transport properties of bare quartz nanopipettes containing aprotic acetonitrile electrolyte can be used discriminate isomers based on polarization and solvation, through changes to interfacial solvent ordering at the nanopore wall. This is demonstrated by monitoring the photoinduced isomerization of spirooxazine to merocyanine using the ion-current rectification of a quartz-nanopipette containing acetonitrile electrolyte, which results in an increase in rectification ratio (RR) from 3.6 ± 0.3 to 5.1 ± 0.2. This change is comparable to traditional UV–Vis absorbance and fluorescence measurements of the same process, with the appearance of a small shoulder-like absorbance peak from 400 to 500 nm, and a strong fluorescence signal at 430 nm.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107820"},"PeriodicalIF":4.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.elecom.2024.107822
Reece Goldsberry , Ulises Martin , Brooke Bond , Evelyn Callaway , Homero Castaneda , Arul Jayaraman
Formed biofilms can induce corrosion of metallic substrates through the secretion of corrosive chemical species, changes in local acidity, and the creation of galvanic oxygen concentration cells. Electrochemical testing is useful to study and monitor the growth of biofilms on metallic substrates. Macroelectrochemical testing gives an average measurement of all the chemical interactions and processes in the sampled area which is typically on the mm2 to cm2 scale. Microcapillary electrochemical droplet cell testing can perform AC and DC electrochemical measurements on the µm2 scale, allowing measurements of local electrochemical processes in the picoampere range. Adapting this technique for use in studying microbiologically induced corrosion could provide high-resolution in-situ characterization of biofilm growth. Low alloy steel coupons were subjected to macro- and microelectrochemical techniques to characterize the influence of microbiological entities on the corrosion process.
{"title":"Applicability of microcapillary electrochemical droplet cell for monitoring microbiologically induced corrosion","authors":"Reece Goldsberry , Ulises Martin , Brooke Bond , Evelyn Callaway , Homero Castaneda , Arul Jayaraman","doi":"10.1016/j.elecom.2024.107822","DOIUrl":"10.1016/j.elecom.2024.107822","url":null,"abstract":"<div><div>Formed biofilms can induce corrosion of metallic substrates through the secretion of corrosive chemical species, changes in local acidity, and the creation of galvanic oxygen concentration cells. Electrochemical testing is useful to study and monitor the growth of biofilms on metallic substrates. Macroelectrochemical testing gives an average measurement of all the chemical interactions and processes in the sampled area which is typically on the mm<sup>2</sup> to cm<sup>2</sup> scale. Microcapillary electrochemical droplet cell testing can perform AC and DC electrochemical measurements on the µm<sup>2</sup> scale, allowing measurements of local electrochemical processes in the picoampere range. Adapting this technique for use in studying microbiologically induced corrosion could provide high-resolution in-situ characterization of biofilm growth. Low alloy steel coupons were subjected to macro- and microelectrochemical techniques to characterize the influence of microbiological entities on the corrosion process.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107822"},"PeriodicalIF":4.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.elecom.2024.107821
Chanyuan Huo , Andrea Vezzoli , Natasa Vasiljevic , Walther Schwarzacher
‘Snapback distance’ refers to the rapid increase in the size of the gap formed immediately after breaking an atomic-scale metallic contact. It is a commonly observed phenomenon in Scanning Tunnelling Microscope break junction (STM-BJ) and mechanically controlled break junction (MCBJ) experiments. Here, we show that the snapback distance measured for a gold break junction in pure water was significantly reduced in an electrolyte containing halide anions. In the case of Br−, experiments under electrochemical control provided clear evidence that this reduction was caused by halide adsorption on the surface of the gold.
{"title":"Halide adsorption influences snapback distance in Scanning Tunnelling Microscope break junctions","authors":"Chanyuan Huo , Andrea Vezzoli , Natasa Vasiljevic , Walther Schwarzacher","doi":"10.1016/j.elecom.2024.107821","DOIUrl":"10.1016/j.elecom.2024.107821","url":null,"abstract":"<div><div>‘Snapback distance’ refers to the rapid increase in the size of the gap formed immediately after breaking an atomic-scale metallic contact. It is a commonly observed phenomenon in Scanning Tunnelling Microscope break junction (STM-BJ) and mechanically controlled break junction (MCBJ) experiments. Here, we show that the snapback distance measured for a gold break junction in pure water was significantly reduced in an electrolyte containing halide anions. In the case of Br<sup>−</sup>, experiments under electrochemical control provided clear evidence that this reduction was caused by halide adsorption on the surface of the gold.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107821"},"PeriodicalIF":4.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.elecom.2024.107812
Malo Duportal, Dao Trinh, Catherine Savall, Xavier Feaugas, Abdelali Oudriss
This work aims to estimate local pH variations of a hydrogen charged sample using Scanning ElectroChemical Microscopy (SECM). For that purpose, the microelectrode is polarized in the cathodic domain, where the proton reduction takes place. An initial calibration suggests that cathodic current of the platinum tip is sensitive to pH variations. Then, this system was applied near the surface of stainless steel previously charged with hydrogen. Coupling this result with the analysis of the uncharged samples at two different pH, it appears that hydrogen desorption induces a local acidification which could explain the increase in dissolution kinetics after hydrogen absorption, which has been reported in many studies.
{"title":"Application of SECM to detect a local electrolyte acidification due to the hydrogen flux desorption from a cathodic charged stainless steel","authors":"Malo Duportal, Dao Trinh, Catherine Savall, Xavier Feaugas, Abdelali Oudriss","doi":"10.1016/j.elecom.2024.107812","DOIUrl":"10.1016/j.elecom.2024.107812","url":null,"abstract":"<div><div>This work aims to estimate local pH variations of a hydrogen charged sample using Scanning ElectroChemical Microscopy (SECM). For that purpose, the microelectrode is polarized in the cathodic domain, where the proton reduction takes place. An initial calibration suggests that cathodic current of the platinum tip is sensitive to pH variations. Then, this system was applied near the surface of stainless steel previously charged with hydrogen. Coupling this result with the analysis of the uncharged samples at two different pH, it appears that hydrogen desorption induces a local acidification which could explain the increase in dissolution kinetics after hydrogen absorption, which has been reported in many studies.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107812"},"PeriodicalIF":4.7,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Voltage fluctuations in energy input not only impact the overall hydrogen production efficiency and stability of Proton Exchange Membrane Water Electrolysis (PEMWE) systems but also pose significant challenges to the long-term service life of individual components. This study focuses on the key component − bipolar plates and investigates the response behavior of platinum-coated titanium bipolar plates under simulated fluctuating voltage conditions. By integrating surface phase analysis and electrochemical testing results, this research elucidates the response characteristics of the bipolar plates to different voltage waveforms and frequencies. And the findings hold substantial significance for the upstream energy control in hydrogen production through water electrolysis.
{"title":"Response characteristics of platinum coated titanium bipolar plates for proton exchange membrane water electrolysis under fluctuating conditions","authors":"Yingyu Ding, Xiejing Luo, Luqi Chang, Chaofang Dong","doi":"10.1016/j.elecom.2024.107819","DOIUrl":"10.1016/j.elecom.2024.107819","url":null,"abstract":"<div><div>Voltage fluctuations in energy input not only impact the overall hydrogen production efficiency and stability of Proton Exchange Membrane Water Electrolysis (PEMWE) systems but also pose significant challenges to the long-term service life of individual components. This study focuses on the key component − bipolar plates and investigates the response behavior of platinum-coated titanium bipolar plates under simulated fluctuating voltage conditions. By integrating surface phase analysis and electrochemical testing results, this research elucidates the response characteristics of the bipolar plates to different voltage waveforms and frequencies. And the findings hold substantial significance for the upstream energy control in hydrogen production through water electrolysis.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107819"},"PeriodicalIF":4.7,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.elecom.2024.107811
Mert Umut Özkaynak , Yurdanur Türker , Koray Bahadır Dönmez , Selin Dağlar , Zehra Çobandede , Merve Metin Çelenk , Nilgün Karatepe , F. Seniha Güner , Ömer Dag
Mesoporous transition metal oxides (TMO) are immensely investigated as electrode materials in supercapacitors. The molten salt assisted self-assembly (MASA) process enables a facile route for the synthesis of the mesoporous TMO. In this study, mesoporous nickel manganese cobaltite (Ni0.5Mn0.5Co2O4) is synthesized for the first time using a MASA process and is evaluated as a novel electrode-active material for asymmetric supercapacitors. The objective of this work is to quantitatively measure the performance improvement in the Ni0.5Mn0.5Co2O4 electrode based on its composition and reveal the improvement mechanism through electrochemical methods. The electrochemical performance of the NiCo2O4 and MnCo2O4 prepared by MASA is also investigated, in order to understand the synergistic effect of Ni and Mn elements in the same cobaltite structure. In line with the data obtained from half cells, a full asymmetric cell is prepared by assembling the appropriate amount of Ni0.5Mn0.5Co2O4 and activated carbon through the charge balance theory. The test results show that the specific capacitance CA (Cs) values are 2.62F/cm2 (92.1F/g) for mesoporous NiCo2O4, 0.26F/cm2 (9.8F/g) for mesoporous MnCo2O4, and 9.53F/cm2 (338.5F/g) for mesoporous Ni0.5Mn0.5Co2O4 under the test conditions of 5 mA/cm2. The asymmetric supercapacitor assembled with Ni0.5Mn0.5Co2O4 and activated carbon demonstrates a superior energy density of 79.52 Wh/kg at 1 mA/cm2. The findings of the study highlight the importance of substituting the electrode with Ni0.5Mn0.5Co2O4 to enhance the CA (Cs) by achieving proper surface properties and electrochemical activity.
介孔过渡金属氧化物（TMO）作为超级电容器的电极材料受到了广泛的研究。熔盐辅助自组装（MASA）工艺是合成介孔过渡金属氧化物的便捷途径。本研究首次采用 MASA 工艺合成了介孔镍锰钴酸盐（Ni0.5Mn0.5Co2O4），并将其作为一种新型电活性材料用于不对称超级电容器的评估。这项工作的目的是根据 Ni0.5Mn0.5Co2O4 电极的组成定量测量其性能改善情况，并通过电化学方法揭示其改善机理。同时还研究了用 MASA 制备的 NiCo2O4 和 MnCo2O4 的电化学性能，以了解镍和锰元素在同一钴酸盐结构中的协同效应。根据半电池获得的数据，通过电荷平衡理论，将适量的 Ni0.5Mn0.5Co2O4 和活性炭组装在一起，制备了全非对称电池。测试结果表明，在 5 mA/cm2 的测试条件下，介孔 NiCo2O4 的比电容 CA (Cs) 值为 2.62F/cm2（92.1F/g），介孔 MnCo2O4 的比电容 CA (Cs) 值为 0.26F/cm2（9.8F/g），介孔 Ni0.5Mn0.5Co2O4 的比电容 CA (Cs) 值为 9.53F/cm2（338.5F/g）。用 Ni0.5Mn0.5Co2O4 和活性炭组装的不对称超级电容器在 1 mA/cm2 的条件下显示出 79.52 Wh/kg 的超高能量密度。研究结果突出了用 Ni0.5Mn0.5Co2O4 替代电极，通过获得适当的表面特性和电化学活性来增强 CA (Cs) 的重要性。
{"title":"Molten Salt Assisted Assembly (MASA) of novel mesoporous Ni0.5Mn0.5Co2O4 for high-performance asymmetric supercapacitors","authors":"Mert Umut Özkaynak , Yurdanur Türker , Koray Bahadır Dönmez , Selin Dağlar , Zehra Çobandede , Merve Metin Çelenk , Nilgün Karatepe , F. Seniha Güner , Ömer Dag","doi":"10.1016/j.elecom.2024.107811","DOIUrl":"10.1016/j.elecom.2024.107811","url":null,"abstract":"<div><div>Mesoporous transition metal oxides (TMO) are immensely investigated as electrode materials in supercapacitors. The molten salt assisted self-assembly (MASA) process enables a facile route for the synthesis of the mesoporous TMO. In this study, mesoporous nickel manganese cobaltite (Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub>) is synthesized for the first time using a MASA process and is evaluated as a novel electrode-active material for asymmetric supercapacitors. The objective of this work is to quantitatively measure the performance improvement in the Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub> electrode based on its composition and reveal the improvement mechanism through electrochemical methods. The electrochemical performance of the NiCo<sub>2</sub>O<sub>4</sub> and MnCo<sub>2</sub>O<sub>4</sub> prepared by MASA is also investigated, in order to understand the synergistic effect of Ni and Mn elements in the same cobaltite structure. In line with the data obtained from half cells, a full asymmetric cell is prepared by assembling the appropriate amount of Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub> and activated carbon through the charge balance theory. The test results show that the specific capacitance <em>C</em><sub><em>A</em></sub> (<em>C<sub>s</sub></em>) values are 2.62F/cm<sup>2</sup> (92.1F/g) for mesoporous NiCo<sub>2</sub>O<sub>4</sub>, 0.26F/cm<sup>2</sup> (9.8F/g) for mesoporous MnCo<sub>2</sub>O<sub>4</sub>, and 9.53F/cm<sup>2</sup> (338.5F/g) for mesoporous Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub> under the test conditions of 5 mA/cm<sup>2</sup>. The asymmetric supercapacitor assembled with Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub> and activated carbon demonstrates a superior energy density of 79.52 Wh/kg at 1 mA/cm<sup>2</sup>. The findings of the study highlight the importance of substituting the electrode with Ni<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>2</sub>O<sub>4</sub> to enhance the <em>C</em><sub><em>A</em></sub> (<em>C<sub>s</sub></em>) by achieving proper surface properties and electrochemical activity.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107811"},"PeriodicalIF":4.7,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1388248124001541/pdfft?md5=7d0f6600dfce9f4681f7e6cf1fbf7f9e&pid=1-s2.0-S1388248124001541-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1016/j.elecom.2024.107810
Tao Chen , Man Li , Joonho Bae
3D petal-shaped Cobalt-doped carbon nanosheets (PCoCNS) were synthesized as excellent sulfur hosts for lithium-sulfur (Li-S) batteries. Co doping enhanced the affinity of the carbon surface for lithium polysulfides (LiPSs), inhibiting the shuttle effect. The electrocatalytic effect of the PCoCNS electrode exhibited enhanced polysulfide conversion kinetics, thereby promoting Li2S formation. Owing to the above advantages, the PCoCNS cathode exhibited satisfactory reversibility of 841 mAh/g with a high capacity retention of 91 %. Additionally, it displayed high coulombic efficiency (CE) values exceeding 97 % over 100 cycles at a current rate of 0.5C. Furthermore, the electrode demonstrated low polarization and exhibited an excellent rate performance, delivering a capacity of 575 mAh/g at the high rate of 3C. This study synthesized a promising sulfur cathode for enhancing the electrochemical performance of Li-S batteries.
{"title":"3D Co-doped carbon nanosheets as high-performance electrodes for Li-S batteries","authors":"Tao Chen , Man Li , Joonho Bae","doi":"10.1016/j.elecom.2024.107810","DOIUrl":"10.1016/j.elecom.2024.107810","url":null,"abstract":"<div><div>3D petal-shaped Cobalt-doped carbon nanosheets (PCoCNS) were synthesized as excellent sulfur hosts for lithium-sulfur (Li-S) batteries. Co doping enhanced the affinity of the carbon surface for lithium polysulfides (LiPSs), inhibiting the shuttle effect. The electrocatalytic effect of the PCoCNS electrode exhibited enhanced polysulfide conversion kinetics, thereby promoting Li<sub>2</sub>S formation. Owing to the above advantages, the PCoCNS cathode exhibited satisfactory reversibility of 841 mAh/g with a high capacity retention of 91 %. Additionally, it displayed high coulombic efficiency (CE) values exceeding 97 % over 100 cycles at a current rate of 0.5C. Furthermore, the electrode demonstrated low polarization and exhibited an excellent rate performance, delivering a capacity of 575 mAh/g at the high rate of 3C. This study synthesized a promising sulfur cathode for enhancing the electrochemical performance of Li-S batteries.</div></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107810"},"PeriodicalIF":4.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Overvoltage and low current are observed for ethanol electrooxidation on the surface of many unmodified electrodes. Therefore, it is desirable to use a suitable catalyst for ethanol electrooxidation to increase the current. This research introduces a new sensor to catalyze ethanol oxidation in an alkaline environment. This new Zn-Mn-Co LDH/PolyPyrrole/GCE nanocomposite sensor exhibits high catalytic activity for ethanol electrooxidation. It changes the oxidation potential of ethanol to a less positive potential. To identify this proposed sensor, X-ray diffraction (XRD), Brauner Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, field emission scanning electron microscopy (FESEM), thermal analysis (TGA), high-resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry techniques were used. Ethanol electrooxidation was investigated by cyclic voltammetry technique. The effects of scan rate and ethanol concentration on the ethanol oxidation peak have been investigated. The proposed sensor showed long-term stability. This prepared nanocomposite can be used as an anode catalyst for ethanol fuel cells.
{"title":"Facile and innovation synthesis of Zn-Mn-Co-LDH/polypyrrole and its application in investigating ethanol oxidation in an alkaline medium","authors":"Elhameh Saeb , Karim Asadpour-Zeynali , Hossein Dastangoo","doi":"10.1016/j.elecom.2024.107809","DOIUrl":"10.1016/j.elecom.2024.107809","url":null,"abstract":"<div><p>Overvoltage and low current are observed for ethanol electrooxidation on the surface of many unmodified electrodes. Therefore, it is desirable to use a suitable catalyst for ethanol electrooxidation to increase the current. This research introduces a new sensor to catalyze ethanol oxidation in an alkaline environment. This new Zn-Mn-Co LDH/PolyPyrrole/GCE nanocomposite sensor exhibits high catalytic activity for ethanol electrooxidation. It changes the oxidation potential of ethanol to a less positive potential. To identify this proposed sensor, X-ray diffraction (XRD), Brauner Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, field emission scanning electron microscopy (FESEM), thermal analysis (TGA), high-resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry techniques were used. Ethanol electrooxidation was investigated by cyclic voltammetry technique. The effects of scan rate and ethanol concentration on the ethanol oxidation peak have been investigated. The proposed sensor showed long-term stability. This prepared nanocomposite can be used as an anode catalyst for ethanol fuel cells.</p></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"167 ","pages":"Article 107809"},"PeriodicalIF":4.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1388248124001528/pdfft?md5=10b6a4972bf9062b9735680a83421d36&pid=1-s2.0-S1388248124001528-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142244174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1016/j.elecom.2024.107808
Zichen Zhang , Jianbang Ge , Biwu Cai , Yang Gao , Zhihao Cheng , Shun Cao , Shuqiang Jiao
Natural convection could arise even at ultra-low redox concentration solutions (1–10 mM). Models such as convection–diffusion layer model and spontaneous convection model have been established to describe this phenomenon. However, the driving forces as well as the parameters that influence this natural convection effects are still not clear. Herein we investigated the effects of viscosity on natural convection by introducing sodium alginate (SA), which enhanced viscosity without changing the diffusion coefficient of the redox couple. Resultantly, it allowed us to obtain the relationship between microscopic flow of solutions and the thickness of natural convection layer. Moreover, wire electrodes with various diameters were also tested to reveal the natural convection effects on mass transfer. An empirical equation was established to describing the influences of solution viscosity and diameter of wire electrode on the thickness of natural convection layer in ultra-low redox concentration solutions.
{"title":"Revisiting the natural convection effects at ultra-low redox concentration solutions: The influence of viscosity and diameter of wire electrode","authors":"Zichen Zhang , Jianbang Ge , Biwu Cai , Yang Gao , Zhihao Cheng , Shun Cao , Shuqiang Jiao","doi":"10.1016/j.elecom.2024.107808","DOIUrl":"10.1016/j.elecom.2024.107808","url":null,"abstract":"<div><p>Natural convection could arise even at ultra-low redox concentration solutions (1–10 mM). Models such as convection–diffusion layer model and spontaneous convection model have been established to describe this phenomenon. However, the driving forces as well as the parameters that influence this natural convection effects are still not clear. Herein we investigated the effects of viscosity on natural convection by introducing sodium alginate (SA), which enhanced viscosity without changing the diffusion coefficient of the redox couple. Resultantly, it allowed us to obtain the relationship between microscopic flow of solutions and the thickness of natural convection layer. Moreover, wire electrodes with various diameters were also tested to reveal the natural convection effects on mass transfer. An empirical equation was established to describing the influences of solution viscosity and diameter of wire electrode on the thickness of natural convection layer in ultra-low redox concentration solutions.</p></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":"168 ","pages":"Article 107808"},"PeriodicalIF":4.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1388248124001516/pdfft?md5=ba0b8e3b61e82fece7cbfa21b163c1cd&pid=1-s2.0-S1388248124001516-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 10.1016/j.elecom.2024.107800
Shumaila Razzaque, Alla Dyachenko, Aimen Waqar, Katarzyna Dusilo, Marcin Opallo
Oxygen reduction is one of the core steps of non-emissive zero carbon energy conversion. Therefore, enhancement of its sluggish kinetics is extremely important. Very recently researchers focused on oxygen electrocatalysis at porous polymers. Here we applied the non-metalated and pyrolysis free hypercrosslinked polymers with high specific surface area and abundant active sites. Electrode modified with the copolymer prepared from the twisted triphenylbenzene and N containing triphenyl amine exhibits electrocatalytic ORR in alkaline medium. Tafel slope value (0.067 V dec−1) indicates the efficient electrocatalytic activity and fast reaction kinetics. The lack of H2O2 product detected by scanning electrochemical microscopy suggests 4-electron path. The electrocatalytic activity of electrodes modified with hypercrosslinked polymers prepared from single monomers is also seen.
氧还原是非辐射零碳能源转换的核心步骤之一。因此，提高其缓慢的动力学极为重要。最近，研究人员重点研究了多孔聚合物的氧电催化。在这里，我们应用了具有高比表面积和丰富活性位点的无金属化、无热解的超交联聚合物。在碱性介质中，使用由扭曲的三苯基苯和含 N 的三苯基胺制备的共聚物修饰的电极表现出电催化 ORR。塔菲尔斜率值（0.067 V dec-1）表明电极具有高效的电催化活性和快速的反应动力学。扫描电化学显微镜检测不到 H2O2 产物，这表明存在 4 电子路径。用单一单体制备的超交联聚合物修饰的电极也具有电催化活性。
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