Journal of Electroanalytical Chemistry最新文献_第10页

Development of new cathode materials for all-iron redox flow batteries using hard carbon-based composites containing niobium pentoxide 利用含五氧化二铌的硬碳基复合材料开发全铁氧化还原液流电池的新型阴极材料

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-10-04 DOI: 10.1016/j.jelechem.2024.118694

Wallace de Jesus Moura , Isabella Campos Batista , Lindomar Gomes De Sousa , Débora Vilela Franco , Rafael Vicentini , Raíssa Venâncio , Hudson Zanin , Leonardo Morais Da Silva

We report in this study new cathodes for all-Fe RFBs synthesized using carbon flakes dispersed in plasticizing and hardening agents to obtain hard and dense carbon (HC) materials in the absence and presence (HC-Nb) of niobium pentoxide (Nb₂O₅). These cathode materials exhibited excellent resistance to wear in acidic solutions and larger potential intervals for water stability (e.g., 1200–1300 mV) compared to conventional graphite (e.g., 800 mV). These characteristics decreased the parasitic occurrence of hydrogen evolution reaction (HER) using a laboratory-made battery cell during the charging process. The latter was based on the Fe⁰/Fe²⁺ and Fe²⁺/Fe³⁺ redox couples present in the anode and cathode compartments, respectively. The different ex-situ and in-situ characterization studies evidenced that the presence of Nb₂O₅ in HCs substantially changed their physicochemical properties. The highest heterogenous kinetic rate constant (k⁰) representing the electrocatalytic activity for electron transfer was verified for the cathode containing 10 wt.% Nb₂O₅. An electromotive force (EMF) of 1.053 V was verified for the fully charged all-Fe RFB. Galvanostatic charge–discharge (GCD) studies revealed excellent coulombic efficiency (> 88 %) after 300 cycles. A pH control by acid addition as a function of the battery operation is necessary to avoid iron hydroxide formation on the anode’s surface.

我们在本研究中报告了使用分散在塑化和硬化剂中的碳片合成的全铁 RFB 的新型阴极，从而在不含或含五氧化二铌（Nb2O5）的情况下（HC-Nb）获得了坚硬致密的碳（HC）材料。与传统石墨（如 800 mV）相比，这些阴极材料在酸性溶液中表现出优异的耐磨性和更大的水稳定性电位间隔（如 1200-1300 mV）。这些特性降低了使用实验室制造的电池在充电过程中发生氢进化反应（HER）的可能性。后者是基于阳极和阴极中分别存在的 Fe0/Fe2+ 和 Fe2+/Fe3+ 氧化还原偶。不同的原位和原位表征研究表明，碳氢化合物中 Nb2O5 的存在大大改变了其物理化学特性。经证实，含有 10 wt.% Nb2O5 的阴极具有最高的异质动力学速率常数 (k0)，代表了电子转移的电催化活性。全铁 RFB 充满电后的电动势（EMF）为 1.053 V。静电充电-放电（GCD）研究表明，经过 300 次循环后，库仑效率极高（88%）。为避免阳极表面形成氢氧化铁，有必要在电池运行过程中通过加酸来控制 pH 值。

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引用次数: 0

Tuning the composition of mixed anthraquinone derivatives towards an affordable flow battery negolyte 调整混合蒽醌衍生物的成分，开发经济实惠的液流电池负极溶解剂

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-10-02 DOI: 10.1016/j.jelechem.2024.118693

Mikhail M. Petrov , Dmitry V. Chikin , Kirill A. Karpenko , Lilia Z. Antipova , Pavel A. Loktionov , Roman D. Pichugov , Alena R. Karastsialiova , Anatoly N. Vereshchagin , Anatoly E. Antipov

Having a long lifespan and being capable of scaling capacity and power independently, redox flow batteries (RFB) offer great opportunities for energy storage. However, the challenge lies in finding an ideal electrolyte. The most mature version of RFB utilizes vanadium solutions and suffers from rising and highly volatile prices of this metal. To address this, organic electrolytes are gaining attention, as they can be obtained from abundant feedstocks. Among those, Anthraquinone-2,7-disulfonic acid (2,7-AQDS) solutions are particularly prominent, demonstrating reversible and fast redox kinetics coupled with reasonable solubility. This paper explores the possibility of synthesizing 2,7-AQDS together with other electroactive compounds (2,6-AQDS, 2-AQS) through the reaction of anthraquinone sulfonation. It shows that obtained mixtures act as electrolytes without any purification or separation, while synthesis conditions can adjust mixture composition and hence their redox behavior. Although the performance of anthraquinone-bromine RFB utilizing these mixtures exhibits a trade-off between power and stability, the best of them are comparable or even superior to 2,7-AQDS. For instance, RFB with a mixture free of 2-AQS demonstrates an energy efficiency of 76.4 % and a capacity fade rate of 0.04 %/cycle at a current density of 75 mA cm⁻². The specific capacity of such mixtures can reach 70 Ah L⁻¹, which makes them promising and affordable RFB negolyte.

氧化还原液流电池（RFB）具有使用寿命长、可独立扩展容量和功率等特点，为能源存储提供了巨大的机遇。然而，挑战在于找到理想的电解质。最成熟的氧化还原液流电池使用钒溶液，但这种金属的价格不断上涨且极不稳定。为了解决这个问题，有机电解质受到越来越多的关注，因为它们可以从丰富的原料中获得。其中，蒽醌-2,7-二磺酸（2,7-AQDS）溶液尤为突出，它具有可逆、快速的氧化还原动力学以及合理的溶解度。本文探讨了通过蒽醌磺化反应将 2,7-AQDS 与其他电活性化合物（2,6-AQDS、2-AQS）合成在一起的可能性。研究表明，获得的混合物可作为电解质使用，无需任何纯化或分离，而合成条件可调整混合物的成分，从而调整其氧化还原行为。虽然使用这些混合物的蒽醌溴 RFB 的性能在功率和稳定性之间有所权衡，但其中最好的混合物与 2,7-AQDS 不相上下，甚至更胜一筹。例如，在电流密度为 75 mA cm-2 时，使用不含 2-AQS 的混合物的 RFB 的能量效率为 76.4%，容量衰减率为 0.04%/周期。这种混合物的比容量可达 70 Ah L-1，因此是一种前景广阔、价格合理的 RFB 负极。

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引用次数: 0

Polyoxometalate-derived anti-aggregation MoC nanoparticles for efficient hydrogen evolution in basic and acidic media 用于在碱性和酸性介质中高效氢气进化的聚氧化金属衍生抗聚集 MoC 纳米粒子

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-10-02 DOI: 10.1016/j.jelechem.2024.118691

Junwei Sun , Xiaoming Li , Yue Wang , Juan Yang , Hongwei Luo , Xiaoyan Zhang , Junfeng Chen

As a cost-effective alternative to Pt-based catalysts, molybdenum carbide (MoC) exhibits considerable potential for catalysing hydrogen evolution reaction (HER) in both alkaline water electrolyzers and proton exchange membrane water electrolyzers. However, achieving ampere-level current densities at low overpotentials remains challenging for MoC-based electrocatalysts. In this study, we utilized electrospinning technology followed by a subsequent heat treatment to successfully synthesize monodisperse MoC nanoparticles (approximately 4.3 nm) embedded in carbon nanofibers. The resultant self-supporting one-dimensional molybdenum carbide@nitrogen-doped carbon nanofiber (MoC-A@NCNF), prepared with polyoxometalate anion (POM) and polyvinylpyrrolidone (PVP), exhibits excellent anti-aggregation behavior. Benefiting from its high specific surface area and one-dimensional conductive network structure, the MoC-A@NCNF displays outstanding hydrogen evolution reaction (HER) performance in both 1 M KOH and 0.5 M H₂SO₄, achieving overpotentials of 491 mV and 568 mV at a current density of 1 A cm⁻², respectively. Furthermore, it exhibits exceptional electrochemical stability during prolonged HER testing under both acidic and alkaline conditions.

碳化钼（MoC）作为铂基催化剂的一种具有成本效益的替代品，在碱性水电解槽和质子交换膜水电解槽中催化氢进化反应（HER）方面具有相当大的潜力。然而，对于基于碳化钼的电催化剂来说，在低过电位下实现安培级的电流密度仍然具有挑战性。在本研究中，我们利用电纺丝技术，随后进行热处理，成功合成了嵌入碳纳米纤维的单分散 MoC 纳米颗粒（约 4.3 nm）。利用聚氧化金属阴离子（POM）和聚乙烯吡咯烷酮（PVP）制备的自支撑一维碳化钼@氮掺杂碳纳米纤维（MoC-A@NCNF）具有优异的抗聚集性能。得益于其高比表面积和一维导电网络结构，MoC-A@NCNF 在 1 M KOH 和 0.5 M H2SO4 中均表现出卓越的氢进化反应（HER）性能，在电流密度为 1 A cm-2 时，过电位分别达到 491 mV 和 568 mV。此外，在酸性和碱性条件下进行长时间的 HER 测试时，它还表现出卓越的电化学稳定性。

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引用次数: 0

First principles study of V2CT2-based MXenes materials in oxygen reduction and oxygen evolution reactions 基于 V2CT2 的 MXenes 材料在氧还原和氧进化反应中的第一性原理研究

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-30 DOI: 10.1016/j.jelechem.2024.118686

Di Zhang , Songshan Gao , Xinyu Yang , Long Lin , Zhongzhou Dong

The development of bifunctional ORR/OER electrocatalysts with low cost, high activity and sustainable cycle plays an important role in improving the performance of new green energy storage and conversion devices to alleviate the energy crisis and environmental pollution. As a graphene-like two-dimensional inorganic layered compound with unique electrochemistry, MXenes materials have attracted more and more attention in the field of electrocatalytic applications. In this paper, based on the first-principles calculation method based on density functional theory (DFT) and quantum mechanics, an effective scheme for designing efficient ORR/OER bifunctional electrocatalysts by introducing Pd/Pt single atoms to regulate the electronic structure of V₂CT₂ (T = O, F) is proposed. Firstly, we discussed the stability of the designed series of single-atom catalysts by calculating the formation energy, binding energy and molecular dynamics simulation. Secondly, by comparing the theoretical overpotentials of these single-atom catalysts for ORR and OER, we found that among the designed SACs, V₂CO₂-Pd, V₂CF₂-Pd and V₂CO₂-V_O-Pt are catalysts with good bifunctional catalytic activity for ORR/OER. Our work provides some guidance for the application of MXenes materials in the field of electrocatalysis.

开发低成本、高活性、可持续循环的双功能 ORR/OER 电催化剂，对于提高新型绿色能源存储和转换装置的性能，缓解能源危机和环境污染具有重要作用。作为一种具有独特电化学性能的类石墨烯二维无机层状化合物，MXenes 材料在电催化应用领域受到越来越多的关注。本文基于密度泛函理论（DFT）和量子力学的第一性原理计算方法，通过引入 Pd/Pt 单原子调控 V2CT2（T = O，F）的电子结构，提出了一种设计高效 ORR/OER 双功能电催化剂的有效方案。首先，我们通过计算单原子催化剂的形成能、结合能和分子动力学模拟，讨论了所设计的一系列单原子催化剂的稳定性。其次，通过比较这些单原子催化剂对 ORR 和 OER 的理论过电位，我们发现在所设计的 SAC 中，V2CO2-Pd、V2CF2-Pd 和 V2CO2-VO-Pt 是对 ORR/OER 具有良好双功能催化活性的催化剂。我们的工作为 MXenes 材料在电催化领域的应用提供了一些指导。

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引用次数: 0

Free gallium (III) determination with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) 利用 AGNES（无梯度和 Nernstian 平衡剥离法）测定游离镓 (III)

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-29 DOI: 10.1016/j.jelechem.2024.118684

Adnívia S.C. Monteiro, Encarna Companys, Jaume Puy, Josep Galceran

Gallium is being extensively used in technological applications. Increasing emissions to the environment classify it as an emerging contaminant. Speciation information, such as the free gallium concentration, [Ga³⁺], is fundamental for understanding/predicting its bioavailability and potential toxicity to biota. In this work, [Ga³⁺] in aqueous solutions at pH 2 and 3 has been measured with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping). The deposition times to reach equilibrium, for a fixed accumulation factor or gain, were longer than those required with other metals such as Zn, Pb, Cd and In. This is attributed to the electrodic irreversibility of the couple Ga⁰/Ga³⁺ on the mercury electrode together with low concentrations of relatively poorly labile and/or poorly reversible (for the electrodic transfer) hydroxy complexes. When the AGNES-SCP variant was applied in the Hanging Mercury Drop Electrode with radius 141 μm, and the transition time was ≤10 s, the correction of the deposited mass with a depletion factor was essential. The speciation capacity of AGNES for Ga was evaluated with the phthalate ligand at pH 3 and the experimental results obtained were very similar to the theoretical results predicted with the stability constants in the NIST and Brown-Ekberg databases.

镓被广泛应用于技术领域。镓在环境中的排放量不断增加，使其成为一种新出现的污染物。游离镓浓度[Ga3+]等规格信息对于了解/预测镓的生物利用率和对生物群的潜在毒性至关重要。在这项工作中，使用 AGNES（无梯度和 Nernstian 平衡剥离）测量了 pH 值为 2 和 3 的水溶液中的 [Ga3+]。在固定的累积因子或增益条件下，达到平衡的沉积时间比其他金属（如锌、铅、镉和铟）所需的时间要长。这归因于汞电极上 Ga0/Ga3+ 对偶的电不可逆性，以及低浓度的相对易变性较差和/或可逆性较差（对于电转移而言）的羟基络合物。当 AGNES-SCP 变体应用于半径为 141 μm 的悬挂式汞滴电极，且过渡时间≤10 秒时，必须使用损耗因子对沉积质量进行校正。利用邻苯二甲酸配体评估了 AGNES 在 pH 值为 3 时对镓的富集能力，实验结果与根据 NIST 和 Brown-Ekberg 数据库中的稳定性常数预测的理论结果非常相似。

{"title":"Free gallium (III) determination with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping)","authors":"Adnívia S.C. Monteiro, Encarna Companys, Jaume Puy, Josep Galceran","doi":"10.1016/j.jelechem.2024.118684","DOIUrl":"10.1016/j.jelechem.2024.118684","url":null,"abstract":"<div><div>Gallium is being extensively used in technological applications. Increasing emissions to the environment classify it as an emerging contaminant. Speciation information, such as the free gallium concentration, [Ga<sup>3+</sup>], is fundamental for understanding/predicting its bioavailability and potential toxicity to biota. In this work, [Ga<sup>3+</sup>] in aqueous solutions at pH2 and 3 has been measured with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping). The deposition times to reach equilibrium, for a fixed accumulation factor or gain, were longer than those required with other metals such as Zn, Pb, Cd and In. This is attributed to the electrodic irreversibility of the couple Ga<sup>0</sup>/Ga<sup>3+</sup> on the mercury electrode together with low concentrations of relatively poorly labile and/or poorly reversible (for the electrodic transfer) hydroxy complexes. When the AGNES-SCP variant was applied in the Hanging Mercury Drop Electrode with radius 141 μm, and the transition time was ≤10 s, the correction of the deposited mass with a depletion factor was essential. The speciation capacity of AGNES for Ga was evaluated with the phthalate ligand at pH 3 and the experimental results obtained were very similar to the theoretical results predicted with the stability constants in the NIST and Brown-Ekberg databases.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118684"},"PeriodicalIF":4.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Physicochemical and electrochemical investigation of lead sulphide-graphene oxide hybrid nanostructure for energy storage applications 用于储能应用的硫化铅-氧化石墨烯混合纳米结构的物理化学和电化学研究

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-28 DOI: 10.1016/j.jelechem.2024.118680

Muhammad Kashif , Shahzaib Khan , Hudeel Wajahat , F.F. Alharbi , Abdullah G. Al-Sehemi , Salma Eman , Hind Alqurashi

The emerging trend of advanced electrodes with greater specific capacitance (C_s) and favourable cycle life is acquiring significant attention of transition metal sulphide composites for energy storage devices. Therefore, this study demonstrates the effective creation of lead sulphide-graphene oxide (PbS/GO) nanohybrid using a simple hydrothermal method, which restricts agglomeration and enhances the electrochemical properties of the developed electrodes. The scanning electron microscopy (SEM) examination verified the distribution of PbS flakes on GO sheets, improving the performance. The nanohybrid employed as an electrode in supercapacitors demonstrated a C_s of 1371.57 F/g at a current density (j) of 1 A/g in a 2.0 M KOH using a three-electrode setup. Remarkably, it retained an exceptional specific capacitance of 94.12 % over 4,000 cycles. Furthermore, the asymmetric configuration (PbS/GO//AC) achieves a more excellent C_s of 251 F/g at 1 A/g and an impressive energy density of 17 Wh/kg when operated at a power density of 252 W/kg. The outstanding electrochemical performance results from the extensive surface area (121.61 m²/g) and mesoporous nature of the hybrid electrode, which provides additional passages and electroactive sites for electrolyte interaction during the oxidation–reduction phenomenon. Additionally, the uniform decoration of PbS nanoflakes on conductive GO nanosheets decreases the agglomeration and contributes to the pseudocapacitive behaviour. Therefore, the exceptional performance of the PbS/GO hybrid electrode holds considerable promise for the advanced supercapacitors used in portable and wearable electronics.

具有更高比电容（Cs）和更长循环寿命的先进电极正成为储能设备中过渡金属硫化物复合材料的重要趋势。因此，本研究采用简单的水热法有效地制备了硫化铅-氧化石墨烯（PbS/GO）纳米杂化物，从而限制了团聚并提高了所开发电极的电化学性能。扫描电子显微镜（SEM）检查验证了 PbS 片在 GO 片上的分布，从而提高了性能。在超级电容器中用作电极的纳米杂化物在三电极设置的 2.0 M KOH 中，电流密度 (j) 为 1 A/g 时的 Cs 值为 1371.57 F/g。值得注意的是，它在 4,000 次循环中保持了 94.12 % 的优异比电容。此外，不对称配置（PbS/GO//AC）在 1 A/g 时的 Cs 值达到了 251 F/g，在 252 W/kg 的功率密度下工作时，能量密度达到了 17 Wh/kg，表现更为出色。出色的电化学性能源于混合电极的大表面积（121.61 m2/g）和介孔性质，这为氧化还原过程中电解质的相互作用提供了额外的通道和电活性位点。此外，PbS 纳米片在导电 GO 纳米片上的均匀装饰减少了团聚，有助于伪电容行为。因此，PbS/GO 混合电极的优异性能为便携式和可穿戴电子设备中使用的先进超级电容器带来了巨大前景。

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引用次数: 0

Porous and defective NiCo2O4 spinel derived from bimetallic NiCo-based Prussian blue analogue for enhanced hydrogen production via the urea electro-oxidation reaction 双金属镍钴基普鲁士蓝类似物衍生的多孔和缺陷镍钴氧化物尖晶石通过尿素电氧化反应提高制氢能力

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-28 DOI: 10.1016/j.jelechem.2024.118687

Xiaolei Zhang , Junyi Ding , Sizhuan Li , Yinpeng Zhang , Shuai Zhang , Minghua Wang , Linghao He , Bin Hu

The efficient hydrogen production via overall water splitting is seriously restrained by the slow kinetics of the oxygen evolution reaction (OER). The substantially low potential for the urea electro-oxidation reaction (UOR) can tackle this problem by replacing the OER at the electrolyzer anode. Herein, the NiCo₂O₄ spinel with rich oxygen vacancies (O_v) and embedded within mesoporous carbon network (O_v-NiCo₂O₄@mC) was derived from NiCo-based Prussian blue analogous (NiCo PBA) and exploited as the bifunctional electrocatalyst of the UOR and OER for boost the hydrogen production via the overall water splitting. Benefiting to the regular skeleton and abundant dual metal sites of NiCo PBA, the derived O_v-NiCo₂O₄@mC comprises abundant oxygen vacancies, lattice defects, and adjustable electron structure. These features afford O_v-NiCo₂O₄@mC the improved UOR ability, showing the potential of 1.33 V versus reversible hydrogen electrode (RHE) at the current density of 10 mA cm⁻², along with a small Tafel slopes of 31 mV dec⁻¹, remarkably lower than that of the OER (1.51 V versus RHE, Tafel slope = 85 mV dec⁻¹). The UOR performance of O_v-NiCo₂O₄@mC substantially outperforms to most of the reported Co and/or Ni-based electrocatalysts. Impressively, the assembled two-electrode urea-assisted overall water splitting device shows the small voltage for the hydrogen production (1.43 V versus RHE) and good long-term stability. The present work can provide a new alternative for the efficient hydrogen production using the MOFs-derivatives.

由于氧进化反应（OER）的动力学速度较慢，通过整体水分裂高效制氢受到严重制约。尿素电氧化反应（UOR）的电位很低，可以通过在电解槽阳极取代 OER 来解决这一问题。在此，从镍钴基普鲁士蓝类似物（NiCo PBA）中衍生出了具有丰富氧空位（Ov）并嵌入介孔碳网络的镍钴氧化物尖晶石（Ov-NiCo2O4@mC），并将其用作尿素电氧化反应和尿素电还原反应的双功能电催化剂，通过整体水分离提高氢气产量。得益于镍钴铅蓝的规则骨架和丰富的双金属位点，衍生出的 Ov-NiCo2O4@mC 具有丰富的氧空位、晶格缺陷和可调电子结构。在 10 mA cm-2 的电流密度下，Ov-NiCo2O4@mC 相对于可逆氢电极（RHE）的电位为 1.33 V，塔菲尔斜率为 31 mV dec-1，明显低于 OER（相对于 RHE 的电位为 1.51 V，塔菲尔斜率 = 85 mV dec-1）。Ov-NiCo2O4@mC 的 UOR 性能大大优于大多数已报道的 Co 和/或 Ni 基电催化剂。令人印象深刻的是，所组装的双电极脲辅助整体水分离装置显示出较小的制氢电压（相对于 RHE 为 1.43 V）和良好的长期稳定性。本研究为利用 MOFs 衍生物高效制氢提供了一种新的选择。

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引用次数: 0

Initial stages of silver electrodeposition on a model Pt(111) single-crystal substrate from ethaline 乙醇在模型 Pt(111) 单晶基底上电沉积银的初始阶段

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-28 DOI: 10.1016/j.jelechem.2024.118688

Elena B. Molodkina, Alexander V. Rudnev, Maria R. Ehrenburg

Deep eutectic solvents (DES) are a new class of solvents with unique properties that are very promising media for the electroplating of metals and alloys. Knowledge about the regularities of metal electrodeposition is noticeably promoted by studies on model single crystal electrodes with a known well-ordered surface structure. In this work, we investigate the regularities of under- and overpotential deposition (upd and opd, respectively) of silver from a silver chloride solution in ethaline on a Pt(111) single crystal surface. For a better understanding of the occurring processes, we employ a complex approach involving electrochemical and in situ and ex situ microscopic techniques. We show that the process of gradual surface poisoning is observed on Pt(111) in the potential range in which no massive solvent degradation is yet observed. We also observe that the extent of this process largely depends on the employed potential of contact between the electrode and the solution and the studied potential range.

The presence of Ag upd on Pt(111) in ethaline is demonstrated using voltammetric and in situ STM data. The available results and charge analysis are used to compare the Ag upd processes in ethaline and in aqueous solutions. We discuss the number of Ag adlayers on Pt(111), the effect of the potential of initial contact of the electrode with the solution and cycling history, and the possibility of anion upd and formation of coadsorbate between Ag adatoms and upd chloride anions (chlorine adatoms). We also demonstrate that upd Ag is not completely desorbed until high anodic potentials, where it seems to catalyze the solvent oxidation. Phase deposition of silver from ethaline on Pt(111) starts at almost zero overpotentials, which is probably related to the presence of the already deposited Ag adlayer. Even at very low overpotentials the deposit includes both large planar 2D crystallites and 3D crystallites formed on the surface defects and at the edges of the flat deposit islands. As the overpotential grows, the epitaxiality is gradually lost; the deposit becomes unshaped and the amount of 3D crystallites and their height increase.

深共晶溶剂（DES）是一类具有独特性质的新型溶剂，是非常有前途的金属和合金电镀介质。通过对具有已知有序表面结构的模型单晶电极进行研究，可以明显促进对金属电沉积规律性的了解。在这项工作中，我们研究了氯化银乙醇溶液中的银在铂(111)单晶表面的欠电位沉积和过电位沉积（分别为upd和opd）的规律性。为了更好地理解发生的过程，我们采用了一种涉及电化学、原位和非原位显微技术的复杂方法。我们发现，在尚未观察到大规模溶剂降解的电位范围内，Pt(111)表面出现了逐渐中毒的过程。我们还观察到，这一过程的程度在很大程度上取决于所使用的电极与溶液之间的接触电位以及所研究的电位范围。现有结果和电荷分析用于比较乙醇和水溶液中的银更新过程。我们讨论了铂(111)上银吸附层的数量、电极与溶液初次接触的电位和循环历史的影响，以及阴离子更新和银原子与更新的氯阴离子（氯原子）之间形成共吸附剂的可能性。我们还证明，更新的银直到高阳极电位才会完全解吸，在高阳极电位下，更新的银似乎会催化溶剂氧化。在过电位几乎为零的情况下，铂（111）上的乙碱银开始相沉积，这可能与已经沉积的银吸附层的存在有关。即使在很低的过电位下，沉积物也包括在表面缺陷和平坦沉积岛边缘形成的大型平面二维结晶和三维结晶。随着过电势的增加，外延性逐渐消失；沉积物变得不规则，三维晶粒的数量和高度增加。

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引用次数: 0

Smartphone-based portable sensor with Bi-MOF nanocomposite for Cd (II) in vegetable samples 基于智能手机的便携式传感器与 Bi-MOF 纳米复合材料，用于检测蔬菜样品中的镉 (II)

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-28 DOI: 10.1016/j.jelechem.2024.118681

Liping Deng , Liangmei Rao , Xinyu Lu , Yutang Wang , Weiming Zhang , Xuemin Duan , Yangping Wen , Zhuohua Kong , Jingkun Xu

The accumulation of heavy metal cadmium (Cd) in the food chain poses a serious threat to human health, necessitating the development of rapid, on-site, and portable detection methods for Cd (II). Herein, we developed a smartphone-based electrochemical sensor for portable determination of Cd (II) in vegetables using a bismuth metal–organic framework (Bi-MOF) nanocomposite. Prismatic rod-like Bi-MOF was hydrothermally synthesized using trimesic acid as organic ligands, and subsequently, carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNTs) were incorporated to form Bi-MOF nanocomposite network. The smartphone-based electrochemical sensor enables rapid, sensitive, and portable detection of Cd (II) in vegetable samples using Bi-MOF/COOH-MWCNTs-modified screen-printed carbon electrodes (SPCE). A comparative analysis of traditional electrochemical sensors coupled with desktop computer for linear voltametric responses for Cd (II) in the range of 0.2–500 ng/mL with a limit of detection (LOD) of 0.07 ng/mL using Bi-MOF/COOH-MWCNTs-modified glassy carbon electrodes (GCE), the portable sensor demonstrated good linear range in 0.7–350 ng/mL with a LOD of 0.22 ng/mL. This work introduces a novel approach for on-site and portable detection of Cd (II) in agricultural products.

重金属镉（Cd）在食物链中的积累对人类健康构成了严重威胁，因此有必要开发快速、现场和便携的镉(II)检测方法。在此，我们利用铋金属有机框架（Bi-MOF）纳米复合材料开发了一种基于智能手机的电化学传感器，用于便携式检测蔬菜中的镉（II）。以三羟甲基氨基甲酸为有机配体，水热合成了棱柱杆状的 Bi-MOF，然后将羧基官能化的多壁碳纳米管（COOH-MWCNTs）加入其中，形成 Bi-MOF 纳米复合网络。这种基于智能手机的电化学传感器利用 Bi-MOF/COOH-MWCNTs 修饰的丝网印刷碳电极 (SPCE) 实现了对蔬菜样品中镉 (II) 的快速、灵敏和便携式检测。使用 Bi-MOF/COOH-MWCNTs 改性的玻璃碳电极（GCE）对传统电化学传感器和台式计算机进行了比较分析，结果表明，该便携式传感器在 0.2-500 纳克/毫升范围内对镉 (II) 具有线性伏安响应，检出限为 0.07 纳克/毫升；在 0.7-350 纳克/毫升范围内具有良好的线性响应，检出限为 0.22 纳克/毫升。这项工作为现场和便携式检测农产品中的镉（II）引入了一种新方法。

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引用次数: 0

Exploiting a carbon black paste electrode modified with palladium nanoparticles entrapped in aluminum hydroxide matrix for selective detection of 2(3)-t-Butyl-4-hydroxyanisole antioxidant in biodiesel samples 利用氢氧化铝基质中夹杂的钯纳米颗粒修饰的炭黑浆电极选择性检测生物柴油样品中的 2(3)-t-Butyl-4-hydroxyanisole 抗氧化剂

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2024-09-28 DOI: 10.1016/j.jelechem.2024.118683

Ricky de La Martini P. Penha , Adeilton P. Maciel , Cícero W.B. Bezerra , Flavio S. Damos , Rita C.S. Luz

A simple and selective method for determination of 2(3)-t-Butyl-4-hydroxyanisole (BHA) based on carbon black (CB) paste electrode modified with Palladium nanoparticles entrapped in aluminum hydroxide matrix (PdNPAH) is described for the first time. The materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The composition of the paste was studied using different amounts of each material. The voltammetric studies of the behavior of BHA on PdNPAH/CBP electrode demonstrated a catalytic activity for the oxidation process of BHA. Also, the voltammetric studies showed that it is possible to determine BHA in presence of 3,5-Di-tert-butyl-4-hydroxytoluene (BHT) and 2-(1,1-Dimethylethyl)-1,4-benzenediol (TBHQ). Under optimized conditions, the method showed a linear response for BHA from 1-5000 µmol/L and a detection limit of 0.20 µmol/L. The proposed method presented good selectivity, precision and it was successfully applied for detection of BHA in biofuel with recovery values from 98.80 % to 105.29 %, showing a good accuracy for the proposed method.

本研究首次描述了一种测定 2(3)-t-Butyl-4-hydroxyanisole (BHA) 的简单选择性方法，该方法基于在氢氧化铝基质中夹杂钯纳米颗粒（PdNPAH）的炭黑（CB）浆状电极。傅立叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对材料进行了表征。使用不同数量的每种材料对浆糊的成分进行了研究。对 BHA 在 PdNPAH/CBP 电极上的行为进行的伏安法研究表明，BHA 的氧化过程具有催化活性。伏安研究还表明，在 3,5- 二叔丁基-4-羟基甲苯（BHT）和 2-(1,1-二甲基乙基)-1,4-苯二酚（TBHQ）存在的情况下，可以测定 BHA。在优化条件下，BHA的线性范围为1-5000 µmol/L，检出限为0.20 µmol/L。该方法具有良好的选择性和精密度，并成功地应用于生物燃料中BHA的检测，回收率为98.80%-105.29%，表明该方法具有良好的准确性。

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引用次数: 0