Pub Date : 2023-08-09DOI: 10.1016/j.jelechem.2023.117699
M. Mallikarjuna, R. Senthamarai
In this paper, an amperometric biosensor model with substrate and product inhibition kinetics is analysed. This model is a steady-state system of reaction-diffusion equations with non-linear terms related to non-Michaelis-Menten kinetics of an enzymatic reaction. We present the approximate analytical expression of the substrate and product concentrations using well-founded methods, namely the Taylors series method (TSM) and the Adomian decomposition method (ADM). These methods proved that they fit for all values of parameters in this model. The steady-state biosensor current, biosensor substrate sensitivity and resistance are also discussed. We also present the numerical solution of the described model using MATLAB programming, and it is noted that there is satisfactory agreement in comparing the analytical solution with numerical results for all possible values of parameters. The effects of the parameters, such as inhibition constants, diffusion parameters, bulk concentration and Michaelis-Menten constant on the sensitivity and the resistance of the biosensor are analysed.
{"title":"An amperometric biosensor and its steady state current in the case of substrate and product inhibition: Taylors series method and Adomian decomposition method","authors":"M. Mallikarjuna, R. Senthamarai","doi":"10.1016/j.jelechem.2023.117699","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117699","url":null,"abstract":"<div><p><span>In this paper, an amperometric biosensor model with substrate and product inhibition kinetics is analysed. This model is a steady-state system of reaction-diffusion equations with non-linear terms related to non-Michaelis-Menten kinetics of an </span>enzymatic reaction. We present the approximate analytical expression of the substrate and product concentrations using well-founded methods, namely the Taylors series method (TSM) and the Adomian decomposition method (ADM). These methods proved that they fit for all values of parameters in this model. The steady-state biosensor current, biosensor substrate sensitivity and resistance are also discussed. We also present the numerical solution of the described model using MATLAB programming, and it is noted that there is satisfactory agreement in comparing the analytical solution with numerical results for all possible values of parameters. The effects of the parameters, such as inhibition constants, diffusion parameters, bulk concentration and Michaelis-Menten constant on the sensitivity and the resistance of the biosensor are analysed.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2308953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-07DOI: 10.1016/j.jelechem.2023.117702
Yanli Zhang, Jiuqing Xiong, Shihai Yan, Bingping Liu
Electrochemical reduction of nitrate to NH3 is a very promising alternative reaction to the Haber-Bosch process, and it is necessary to develop the efficient electrocatalysts. In this study, a particle-support mode Co3O4 catalyst was synthesized with ZIF-67 as the precursor, and then dispersed on MoS2 nanoflowers by hydrothermal method. The Co3O4 is anchored to MoS2 by forming Co-S coordination bond. Furthermore, the particle-supported Co3O4 exhibits better performance than Co3O4 alone, as is manifested by higher Faradaic efficiencies and NH3 yield rate at − 0.64 V (52.69% vs 32.03%; 4539.61 μg h−1 mg−1cat vs 2048.63 μg h−1 mg−1cat), lower energy barriers (0.96 eV vs 1.19 eV), and better electronic conductivity (Bandwidth: 0.581 eV vs 0.613 eV). In addition, this research provides an effective solution to solve the aggregation problem of metal oxide nanoparticles.
电化学还原硝态氮为NH3是一种很有前途的替代Haber-Bosch法的反应,有必要开发高效的电催化剂。本研究以ZIF-67为前驱体合成了一种颗粒支撑型Co3O4催化剂,并通过水热法将其分散在MoS2纳米花上。Co3O4通过形成Co-S配位键锚定在MoS2上。此外,颗粒负载的Co3O4比单独的Co3O4表现出更好的性能,表现在- 0.64 V时更高的法拉第效率和NH3产率(52.69% vs 32.03%;4539.61 μg h−1 mg−1cat vs 2048.63 μg h−1 mg−1cat),更低的能垒(0.96 eV vs 1.19 eV)和更好的电子导电性(带宽:0.581 eV vs 0.613 eV)。此外,本研究为解决金属氧化物纳米颗粒的聚集问题提供了有效的解决方案。
{"title":"Promotion of nitrate reduction reaction activity by Co3O4@MoS2 Particle-Support system","authors":"Yanli Zhang, Jiuqing Xiong, Shihai Yan, Bingping Liu","doi":"10.1016/j.jelechem.2023.117702","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117702","url":null,"abstract":"<div><p>Electrochemical reduction of nitrate to NH<sub>3</sub> is a very promising alternative reaction to the Haber-Bosch process, and it is necessary to develop the efficient electrocatalysts. In this study, a particle-support mode Co<sub>3</sub>O<sub>4</sub> catalyst was synthesized with ZIF-67 as the precursor, and then dispersed on MoS<sub>2</sub> nanoflowers by hydrothermal method. The Co<sub>3</sub>O<sub>4</sub> is anchored to MoS<sub>2</sub> by forming Co-S coordination bond. Furthermore, the particle-supported Co<sub>3</sub>O<sub>4</sub> exhibits better performance than Co<sub>3</sub>O<sub>4</sub> alone, as is manifested by higher Faradaic efficiencies and NH<sub>3</sub> yield rate at − 0.64 V (52.69% vs 32.03%; 4539.61 μg h<sup>−1</sup> mg<sup>−1</sup><sub>cat</sub> vs 2048.63 μg h<sup>−1</sup> mg<sup>−1</sup><sub>cat</sub>), lower energy barriers (0.96 eV vs 1.19 eV), and better electronic conductivity (Bandwidth: 0.581 eV vs 0.613 eV). In addition, this research provides an effective solution to solve the aggregation problem of metal oxide nanoparticles.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3208716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-07DOI: 10.1016/j.jelechem.2023.117709
Dušan Mladenović , Ana Mladenović , Diogo M.F. Santos , Ayşe B. Yurtcan , Šćepan Miljanić , Slavko Mentus , Biljana Šljukić
Among many alternatives to fossil fuel-based energy systems, one of the most promising is based on hydrogen energy and its production and use in unitized regenerative fuel cells as the primary energy conversion devices. However, there are some setbacks and challenges when designing suitable and efficient electrocatalysts for these devices. The most effective and durable catalysts are based on platinum–group metals, with low abundance and unbearably high prices. Many attempts were undertaken to overcome this setback by designing catalysts suitable for massive commercial use. This review paper focuses on recent advances in developing bifunctional catalysts for oxygen reduction and oxygen evolution catalysis in alkaline media, based on abundant transition metal oxides (TMOs): MnO2, NiO, and TiO2. The problem of unifying parameters to compare the effectiveness of different electrocatalysts is emphasized. This review discusses the most promising alternative bifunctional electrocatalysts by comparing the performance of TMOs with some precious metal catalysts used as benchmarks.
{"title":"Transition metal oxides for bifunctional ORR/OER electrocatalysis in unitized regenerative fuel cells","authors":"Dušan Mladenović , Ana Mladenović , Diogo M.F. Santos , Ayşe B. Yurtcan , Šćepan Miljanić , Slavko Mentus , Biljana Šljukić","doi":"10.1016/j.jelechem.2023.117709","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117709","url":null,"abstract":"<div><p>Among many alternatives to fossil fuel-based energy systems, one of the most promising is based on hydrogen energy and its production and use in unitized regenerative fuel cells as the primary energy conversion devices. However, there are some setbacks and challenges when designing suitable and efficient electrocatalysts for these devices. The most effective and durable catalysts are based on platinum–group metals, with low abundance and unbearably high prices. Many attempts were undertaken to overcome this setback by designing catalysts suitable for massive commercial use. This review paper focuses on recent advances in developing bifunctional catalysts for oxygen reduction and oxygen evolution catalysis in alkaline media, based on abundant transition metal oxides (TMOs): MnO<sub>2</sub>, NiO, and TiO<sub>2</sub>. The problem of unifying parameters to compare the effectiveness of different electrocatalysts is emphasized. This review discusses the most promising alternative bifunctional electrocatalysts by comparing the performance of TMOs with some precious metal catalysts used as benchmarks.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2907079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-07DOI: 10.1016/j.jelechem.2023.117710
Yi-Chao Wang , Liang Wen , Zhi-Wei Liu , Peng Xu , Si-Lai Zheng , Ming-Guang Liu , Ji-Zhou Kong , Qian-Zhi Wang , Hong-Yu Wei , Fei Zhou , Kostya Ken Ostrikov
Safety issues of common rechargeable Li-ion batteries (LIB) necessitate urgent development of alternative high-performance electrode materials. Lithiated nickel-rich oxides (LiNi1-x-yMnxCoyO2) are promising LIB cathode materials, but they suffer from structural instabilities causing major capacity loss. To address this issue, here we use a robust ethanol-based wet coating process to coat a LiNi0.8Co0.1Mn0.1O2 LIB cathode material with polyanionic compound TiP2O7. The coating layer does not affect the phase structure of LiNi0.8Co0.1Mn0.1O2 and ensures a remarkable electrochemical performance, evidenced by the high initial Coulombic efficiency, durable cyclic stability, and excellent rate performance. The mechanisms leading to the achieved improvements are related to the effects of the coating layer which improved the Li+ diffusion capability and the electrochemical polarization. The TiP2O7 layer protects the electrode from the electrolyte by suppressing side reactions such as HF acidic attack and the associated dissolution of transition metal ion. Moreover, the unique three-dimensional (XOn)m- framework of the TiP2O7 polyanion provides plentiful accommodation sites and channels for the Li-ions diffusion. The demonstrated approach opens new avenues for practical applications of electrochemically active coatings in diverse energy storage devices and systems.
{"title":"Improving electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathode via polyanionic TiP2O7 coating","authors":"Yi-Chao Wang , Liang Wen , Zhi-Wei Liu , Peng Xu , Si-Lai Zheng , Ming-Guang Liu , Ji-Zhou Kong , Qian-Zhi Wang , Hong-Yu Wei , Fei Zhou , Kostya Ken Ostrikov","doi":"10.1016/j.jelechem.2023.117710","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117710","url":null,"abstract":"<div><p>Safety issues of common rechargeable Li-ion batteries (LIB) necessitate urgent development of alternative high-performance electrode materials. Lithiated nickel-rich oxides (LiNi<sub>1-x-y</sub>Mn<sub>x</sub>Co<sub>y</sub>O<sub>2</sub>) are promising LIB cathode materials, but they suffer from structural instabilities causing major capacity loss. To address this issue, here we use a robust ethanol-based wet coating process to coat a LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> LIB cathode material with polyanionic compound TiP<sub>2</sub>O<sub>7.</sub> The coating layer does not affect the phase structure of LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> and ensures a remarkable electrochemical performance, evidenced by the high initial Coulombic efficiency, durable cyclic stability, and excellent rate performance. The mechanisms leading to the achieved improvements are related to the effects of the coating layer which improved the Li<sup>+</sup> diffusion capability and the electrochemical polarization. The TiP<sub>2</sub>O<sub>7</sub> layer protects the electrode from the electrolyte by suppressing side reactions such as HF acidic attack and the associated dissolution of transition metal ion. Moreover, the unique three-dimensional (XO<sub>n</sub>)<sup>m-</sup> framework of the TiP<sub>2</sub>O<sub>7</sub> polyanion provides plentiful accommodation sites and channels for the Li-ions diffusion. The demonstrated approach opens new avenues for practical applications of electrochemically active coatings in diverse energy storage devices and systems.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3407119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-07DOI: 10.1016/j.jelechem.2023.117712
Qinting Su , Songde Huang , Jinlong Liao, Dakun Song, Wenjie Yuan, Cuihua Li, Jinhua He
In recent years, rechargeable lithium-ion batteries (LIBs) have been extensively studied and applied in portable electronics, electric vehicles, and new energy storage devices. Gel polymer electrolytes (GPEs), currently a research hotspot, inherit the high ionic conductivity of liquid electrolytes and great mechanical properties and safety of solid electrolytes, exhibiting great application potential. Herein, we demonstrate a flexible flame retardant GPE (PPC37) that forms a polymer network through intermolecular hydrogen bonding. During the charge–discharge cycle, the formation of a LiF-rich solid electrolyte interface (SEI) facilitates the uniform electrochemical deposition of Li+ and achieves a long life cycle without dendrites. PPC37 possesses high ionic conductivity (1.06 mS cm−1 at 25 °C) and robust mechanical properties (198% fracture length and 2.43 MPa fracture strength). The Li|PPC37|LiFePO4 batteries presented great cycling stability with an initial capacity of 151.9 mAh/g and a discharge capacity retention of 86.4% after 500 cycles at a high current density of 3C at 55 °C. The excellent thermal stability, interfacial stability, flame retardancy, flexibility and electrochemical stability demonstrated with PPC37 demonstrate the safety of high-temperature batteries, indicating their great application potential in flexible electronic devices and high-temperature environments.
近年来,可充电锂离子电池(lib)在便携式电子产品、电动汽车和新型储能设备中得到了广泛的研究和应用。凝胶聚合物电解质(GPEs)继承了液体电解质的高离子电导率和固体电解质良好的力学性能和安全性,是目前的研究热点,具有很大的应用潜力。在这里,我们展示了一种柔性阻燃剂GPE (PPC37),它通过分子间氢键形成聚合物网络。在充放电循环过程中,富lif固体电解质界面(SEI)的形成有利于Li+的均匀电化学沉积,实现无枝晶的长寿命周期。PPC37具有高离子电导率(25°C时为1.06 mS cm−1)和坚固的力学性能(断裂长度为198%,断裂强度为2.43 MPa)。Li|PPC37|LiFePO4电池具有良好的循环稳定性,在55°C的高电流密度下,循环500次后,初始容量为151.9 mAh/g,放电容量保持率为86.4%。PPC37所表现出的优异的热稳定性、界面稳定性、阻燃性、柔韧性和电化学稳定性证明了高温电池的安全性,表明其在柔性电子器件和高温环境中的巨大应用潜力。
{"title":"A flame retardant and flexible gel polymer electrolytes for high temperature lithium metal batteries","authors":"Qinting Su , Songde Huang , Jinlong Liao, Dakun Song, Wenjie Yuan, Cuihua Li, Jinhua He","doi":"10.1016/j.jelechem.2023.117712","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117712","url":null,"abstract":"<div><p>In recent years, rechargeable lithium-ion batteries (LIBs) have been extensively studied and applied in portable electronics, electric vehicles, and new energy storage devices. Gel polymer electrolytes (GPEs), currently a research hotspot, inherit the high ionic conductivity of liquid electrolytes and great mechanical properties and safety of solid electrolytes, exhibiting great application potential. Herein, we demonstrate a flexible flame retardant GPE (PPC37) that forms a polymer network through intermolecular hydrogen bonding. During the charge–discharge cycle, the formation of a LiF-rich solid electrolyte interface (SEI) facilitates the uniform electrochemical deposition of Li<sup>+</sup> and achieves a long life cycle without dendrites. PPC37 possesses high ionic conductivity (1.06 mS cm<sup>−1</sup> at 25 °C) and robust mechanical properties (198% fracture length and 2.43 MPa fracture strength). The Li|PPC37|LiFePO<sub>4</sub> batteries presented great cycling stability with an initial capacity of 151.9 mAh/g and a discharge capacity retention of 86.4% after 500 cycles at a high current density of 3C at 55 °C. The excellent thermal stability, interfacial stability, flame retardancy, flexibility and electrochemical stability demonstrated with PPC37 demonstrate the safety of high-temperature batteries, indicating their great application potential in flexible electronic devices and high-temperature environments.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3276172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-06DOI: 10.1016/j.jelechem.2023.117705
Mehar Un Nisa , Karam Jabbour , Sumaira Manzoor , Khaled Fahmi Fawy , Abdul Ghafoor Abid , Fayyaz Hussain , Shaimaa A.M. Abdelmohsen , Meznah M. Alanazi , Muhammad Naeem Ashiq
Development of an effective electrocatalyst for the electrochemical water splitting to store electrical energy as H2 fuel and improve sluggish oxygen evolution reaction (OER) is the need of the time. For H2 production and making it more accessible, developing a low-cost fabrication method for an efficient OER catalyst with characteristics including a large surface area, an abundance of active sites, and exceptional stability is necessary. In this study, neodymium-doped manganese oxide (Nd-MnO) with a larger specific surface area (32.6 m2/g), small size particles (84 nm), and most crucially high concentration of oxygen vacancies fabricated via a simple solution reduction method using NaBH4 as a reductant. Nd-MnO has an overpotential of 394 mV and a Tafel slope value of 84 mV/dec reaching 10 mA/cm2, superior to RuO2 and MnO. The potential results of the Nd-MnO are due to a unique structure consisting of nanocubes that may enhance OH ion mass diffusion/transport and offer a large number of active sites for catalysis of OER, as well as oxygen vacancies which are also validated by DFT that may enhance the electronic conductivity and provide H2O adsorption on the surface of neighboring Mn3+ sites.
{"title":"Facile cubic Nd doped MnO nanostructure synthesis as effective electrocatalyst for oxygen evolution reaction","authors":"Mehar Un Nisa , Karam Jabbour , Sumaira Manzoor , Khaled Fahmi Fawy , Abdul Ghafoor Abid , Fayyaz Hussain , Shaimaa A.M. Abdelmohsen , Meznah M. Alanazi , Muhammad Naeem Ashiq","doi":"10.1016/j.jelechem.2023.117705","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117705","url":null,"abstract":"<div><p>Development of an effective electrocatalyst for the electrochemical water splitting to store electrical energy as H<sub>2</sub> fuel and improve sluggish oxygen evolution reaction (OER) is the need of the time. For H<sub>2</sub> production and making it more accessible, developing a low-cost fabrication method for an efficient OER catalyst with characteristics including a large surface area, an abundance of active sites, and exceptional stability is necessary. In this study, neodymium-doped manganese oxide (Nd-MnO) with a larger specific surface area (32.6 m<sup>2</sup>/g), small size particles (84 nm), and most crucially high concentration of oxygen vacancies fabricated via a simple solution reduction method using NaBH<sub>4</sub> as a reductant. Nd-MnO has an overpotential of 394 mV and a Tafel slope value of 84 mV/dec reaching 10 mA/cm<sup>2</sup>, superior to RuO<sub>2</sub> and MnO. The potential results of the Nd-MnO are due to a unique structure consisting of nanocubes that may enhance OH ion mass diffusion/transport and offer a large number of active sites for catalysis of OER, as well as oxygen vacancies which are also validated by DFT that may enhance the electronic conductivity and provide H<sub>2</sub>O adsorption on the surface of neighboring Mn<sup>3+</sup> sites.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3461054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon layer-encompassed nickel nanoparticles of core–shell structure (designated as Ni NPs@NC) show notable advantages toward electrochemical carbon dioxide reduction reaction (CO2RR). Core-shell structured Ni NPs@NC nanoparticles anchored on the carbon matrix have been conveniently built from a cationic metal–organic framework (CPM-72 herein) which incorporates the Ni2+ cations through the cation exchange before high-temperature pyrolysis. The designed Ni NPs@NC catalyst exhibited impressive CO2RR performance which could efficiently convert CO2 into CO (carbon monoxide). In the H-type cell, a maximal CO faradaic efficiency (FE) of 86.4% was achieved at −0.8 V (vs. RHE) with a high CO partial current density (jco) of −11.0 mA cm−2. In the flow cell device, the CO FE was further improved to 98.6% with the enhanced jco of −38.7 mA cm−2. Finally, Zn-CO2 battery test also delivered a peak power density of 0.39 mW cm−2 at 2.65 mA cm−2.
碳层包覆的核壳结构镍纳米粒子(指定为Ni NPs@NC)在电化学二氧化碳还原反应(CO2RR)中表现出显著的优势。在高温热解前,通过阳离子交换将Ni2+离子吸附在阳离子金属-有机骨架(CPM-72)上,制备了锚定在碳基体上的核壳结构Ni NPs@NC纳米颗粒。所设计的Ni NPs@NC催化剂表现出令人印象深刻的CO2RR性能,可以有效地将CO2转化为CO(一氧化碳)。在h型电池中,在−0.8 V(相对于RHE)和较高的CO分电流密度(jco)为−11.0 mA cm−2时,CO的法拉第效率(FE)达到了86.4%。在流式电池装置中,当jco增加到−38.7 mA cm−2时,CO FE进一步提高到98.6%。最后,锌- co2电池在2.65 mA cm - 2下的峰值功率密度为0.39 mW cm - 2。
{"title":"Nitrogen-doped carbon-encompassed Ni nanoparticles prepared from Ni (II) cation-exchanged metal organic framework for efficient electrochemical CO2 reduction","authors":"Feng Chen , Li-Li Zhang , Ke-An Wang, Guan-Rong Zhu, Hai-Bin Zhu","doi":"10.1016/j.jelechem.2023.117704","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117704","url":null,"abstract":"<div><p>Carbon layer-encompassed nickel nanoparticles of core–shell structure (designated as Ni NPs@NC) show notable advantages toward electrochemical carbon dioxide reduction reaction (CO<sub>2</sub>RR). Core-shell structured Ni NPs@NC nanoparticles anchored on the carbon matrix have been conveniently built from a cationic metal–organic framework (CPM-72 herein) which incorporates the Ni<sup>2+</sup> cations through the cation exchange before high-temperature pyrolysis. The designed Ni NPs@NC catalyst exhibited impressive CO<sub>2</sub>RR performance which could efficiently convert CO<sub>2</sub> into CO (carbon monoxide). In the H-type cell, a maximal CO faradaic efficiency (FE) of 86.4% was achieved at −0.8 V (vs. RHE) with a high CO partial current density (<em>j</em><sub>co</sub>) of −11.0 mA cm<sup>−2</sup>. In the flow cell device, the CO FE was further improved to 98.6% with the enhanced <em>j</em><sub>co</sub> of −38.7 mA cm<sup>−2</sup>. Finally, Zn-CO<sub>2</sub> battery test also delivered a peak power density of 0.39 mW cm<sup>−2</sup> at 2.65 mA cm<sup>−2</sup>.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2308946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-06DOI: 10.1016/j.jelechem.2023.117700
Nan Zhang , Lingyun Cui , Xiaohui Yu , Qiaozhen Yu , Jianwei Zhao
Nanosized-silver substrates with smooth surface and fine particles were fabricated by a non-cyanide pulse electrochemical deposition. The electrochemical behavior of silver electrochemical deposition was investigated with a series of electrochemical methods. Cyclic Voltammetry and chronopotentiometry showed that the overpotential was significantly reduced when silver ions were continuously deposited on the silver layer. During deposition, the nucleation mechanism gradually changed from the progressive nucleation to the instantaneous nucleation with the negative shift of potential. The effect of pulse period θ on the Surface Enhanced Raman Scattering performance of the substrate was investigated. Combined with Scanning Electron Microscope, X-ray diffraction, 2D SERS Mapping and Raman spectrum, the pulse period θ was optimized. The enhancement effect of the substrates was relatively uniform, and the enhancement factor for rhodamine 6G was 5.34 × 106, the detection limit could be as low as 1.0 × 10−13 mol·L−1. The optimized substrate obtained good linear range and low detection limit in the detection of contraband pigment sunset yellow, indicating that the substrate may have a good application prospect in the actual detection.
{"title":"Fabrication of blue silver substrate with 10 nm grains by an electrochemical deposition and application in SERS","authors":"Nan Zhang , Lingyun Cui , Xiaohui Yu , Qiaozhen Yu , Jianwei Zhao","doi":"10.1016/j.jelechem.2023.117700","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117700","url":null,"abstract":"<div><p>Nanosized-silver substrates with smooth surface and fine particles were fabricated by a non-cyanide pulse electrochemical deposition. The electrochemical behavior of silver electrochemical deposition was investigated with a series of electrochemical methods. Cyclic Voltammetry and chronopotentiometry showed that the overpotential was significantly reduced when silver ions were continuously deposited on the silver layer. During deposition, the nucleation mechanism gradually changed from the progressive nucleation to the instantaneous nucleation with the negative shift of potential. The effect of pulse period <em>θ</em> on the Surface Enhanced Raman Scattering performance of the substrate was investigated. Combined with Scanning Electron Microscope, X-ray diffraction, 2D SERS Mapping and Raman spectrum, the pulse period <em>θ</em> was optimized. The enhancement effect of the substrates was relatively uniform, and the enhancement factor for rhodamine 6G was 5.34 × 10<sup>6</sup>, the detection limit could be as low as 1.0 × 10<sup>−13</sup> mol·L<sup>−1</sup>. The optimized substrate obtained good linear range and low detection limit in the detection of contraband pigment sunset yellow, indicating that the substrate may have a good application prospect in the actual detection.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2907089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-05DOI: 10.1016/j.jelechem.2023.117707
Dongil Kim , Hee-Jo Lee , Bo-Hye Kim
N-rich multilayered carbon nanofibers with hollow channels (PPMPN) are fabricated to fully utilize the mesopores, micropores, and nitrogen-functional groups of carbon nanofibers (CNFs) for superior electrochemical properties. Among all composites, the PPMPN(10) exhibits high specific surface area (570 m2g−1) with mesopore volume fraction (42%) and rich surface functionalities (∼7.25at% nitrogen and ∼ 16.1at% oxygen), helping to improve electrochemical performance. The performance of the symmetric supercapacitor of the PPMPN was significantly improved in terms of its specific capacitance of 189 Fg−1 at 1 mAcm−2, good retention of 80% (when the current density is increased from 1 to 20 mAcm−2), energy density of 23.5 Whkg−1 at a power density of 400 Wkg−1, and cycling stability of 94% for 10,000 cycles. The top layer plays a role in charge storage/transport by increasing electrical conductivity due to N-functional groups. The intermediate layer with tubular 1D nanostructures enhances the diffusion of electrolyte ions even at higher current densities. The bottom layer composed of numerous micropores serves as a charge storage layer. Therefore, in the multilayer CNF, the micropores/mesopores and N-functional properties of each layer do not interfere with each other, and the advantages of the factors of each layer are maximized in the electrochemical properties.
{"title":"Synergistically enhanced electrochemical performance using N-rich multilayered carbon nanofibers","authors":"Dongil Kim , Hee-Jo Lee , Bo-Hye Kim","doi":"10.1016/j.jelechem.2023.117707","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117707","url":null,"abstract":"<div><p><em>N</em>-rich multilayered carbon nanofibers with hollow channels (PPMPN) are fabricated to fully utilize the mesopores, micropores, and nitrogen-functional groups of carbon nanofibers (CNFs) for superior electrochemical properties. Among all composites, the PPMPN(10) exhibits high specific surface area (570 m<sup>2</sup>g<sup>−1</sup>) with mesopore volume fraction (42%) and rich surface functionalities (∼7.25at% nitrogen and ∼ 16.1at% oxygen), helping to improve<!--> <!-->electrochemical performance. The performance of the symmetric supercapacitor of the PPMPN was significantly improved in terms of its specific capacitance of 189 Fg<sup>−1</sup> at 1 mAcm<sup>−2</sup>, good retention of 80% (when the current density is increased from 1 to 20 mAcm<sup>−2</sup>), energy density of 23.5 Whkg<sup>−1</sup> at a power density of 400 Wkg<sup>−1</sup>, and cycling stability of 94% for 10,000 cycles. The top layer plays a role in charge storage/transport by increasing electrical conductivity due to <em>N</em>-functional groups. The intermediate layer with tubular 1D nanostructures enhances the diffusion of electrolyte ions even at higher current densities. The bottom layer composed of numerous micropores serves as a charge storage layer. Therefore, in the multilayer CNF, the micropores/mesopores and <em>N</em>-functional properties of each layer do not interfere with each other, and the advantages of the factors of each layer are maximized in the electrochemical properties.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2249235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1016/j.jelechem.2023.117701
Dalal A. Alshammari , Yasser M. Riyad , Salma Aman , Naseeb Ahmad , Hafiz Muhammad Tahir Farid , Zeinhom M. El-Bahy
In the wake of environmental enigmas including global warming and the exhaustion of traditional hydrocarbon sediments, the usage of eco-friendly power generation is of paramount importance today. Alternatives to traditional fossil fuels such as hydrogen are clean, safe, and environmentally friendly. Moreover, hydrogen as a renewable energy source, as the only by product of burning hydrogen is water. Many electrochemical energy conversion methods rely on the oxygen evolution reaction (OER), but creating effectual, economical electrocatalysts for it has proven difficult. The multifunctional electrocatalyst, nickel selenide-anchored cobalt telluride, has been found to be effective in catalyzing oxygen evolution processes in alkaline medium. CoTe and NiSe, generated hydrothermally, exhibit promising electrocatalytic activity. However, their composite NiSe@CoTe, possesses higher OER durability. The presence of NiSe in the CoTe matrix responses a powerful OER responses due to the synergistic effect in alkaline environment. The NiSe@CoTe nanocomposite shows minimal Tafel value (39 mV/dec) and lower overpotential (247 mV) to attain a current density of 10 mA/cm2, whereas the pristine CoTe and NiSe needed higher overpotential to attain same current density. Following 16 h of utilizing the same catalyst, OER stability was maintained with 88 % current density retention.
{"title":"Tuning the electrocatalytic efficacy of nano-dumbbell shaped nickel selenide anchored cobalt telluride towards oxygen evolution","authors":"Dalal A. Alshammari , Yasser M. Riyad , Salma Aman , Naseeb Ahmad , Hafiz Muhammad Tahir Farid , Zeinhom M. El-Bahy","doi":"10.1016/j.jelechem.2023.117701","DOIUrl":"https://doi.org/10.1016/j.jelechem.2023.117701","url":null,"abstract":"<div><p>In the wake of environmental enigmas including global warming and the exhaustion of traditional hydrocarbon sediments, the usage of eco-friendly power generation is of paramount importance today. Alternatives to traditional fossil fuels such as hydrogen are clean, safe, and environmentally friendly. Moreover, hydrogen as a renewable energy source, as the only by product of burning hydrogen is water. Many electrochemical energy conversion methods rely on the oxygen evolution reaction (OER), but creating effectual, economical electrocatalysts for it has proven difficult. The multifunctional electrocatalyst, nickel selenide-anchored cobalt telluride, has been found to be effective in catalyzing oxygen evolution processes in alkaline medium. CoTe and NiSe, generated hydrothermally, exhibit promising electrocatalytic activity. However, their composite NiSe@CoTe, possesses higher OER durability. The presence of NiSe in the CoTe matrix responses a powerful OER responses due to the synergistic effect in alkaline environment. The NiSe@CoTe nanocomposite shows minimal Tafel value (39 mV/dec) and lower overpotential (247 mV) to attain a current density of 10 mA/cm<sup>2</sup>, whereas the pristine CoTe and NiSe needed higher overpotential to attain same current density. Following 16 h of utilizing the same catalyst, OER stability was maintained with 88 % current density retention.</p></div>","PeriodicalId":50545,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2249237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}