JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2022
·Vol. 53
·期 4
·847-860
·
IF 2.925
Liu Zuowei,Guo Xueyi,Tian Qinghua,Xu Zhipeng
Abstract The gallium electrowinning process is always accompanied by hydrogen evolution reaction that results in low current efficiency (CE). In this manuscript, cyclic voltammetry and chronoamperometry studies were carried out to investigate the gallium cathode behavior under various conditions and explore the parameter that is beneficial to improve the CE. The CE of the lead and copper cathodes was higher, while gallium deposited on the titanium, SUS316, and SUS304 cathodes was readily separated. Increasing the overpotential and gallium concentration or decreasing the pH within a certain range was all beneficial to improve the CE, while the temperature had no significant effect on the CE. Kinetic studies of gallium electrodeposition were carried out. The gallium electrodeposition process was determined as mixed control and forced convection is expected to further improve the CE. The apparent activation energy and kinetic current from the electrochemical reactions were determined to be 23.335 kJ mol −1 and 47.6 mA, respectively. Graphical abstract
研究领域:
电化学
·
材料科学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2014
·
IF 3.107
Li Wang,Lei Xu
A novel method for the selective extraction of free (pH 8.4) and total sulfite (pH 11.0) from muscle foods and the following determination by a voltammetric sensor was reported. The proposed method was based on the eletrocatalytic oxidation of sulfite at modified glassy carbon electrode (GCE) fabricated by immobilizing 9 μg of acetylferrocene on the surface of GCE along with 35 μg of carbon black to improve the electron transfer within poly(vinyl butyral) membrane matrix. The external standard calibration curve was linear in the range of 0.03–4.0 mmol L–1 with a detection limit of 15 μmol L–1. This method had been applied to the determination of free and total sulfite in shrimp muscle fortified samples and compared with an ion chromatography method. The proposed electrode and analysis methods were proven to be sensitive, accurate, and rapid and exhibited very good reproducibility and stability under the used conditions.
研究领域:
食品科学
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电化学分析
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2020
·Vol. 167
·期 2
·027517
·
IF 3.721
Yaru Hu,Kun Zhao,Feng Gao,Jin Zhang,Dexin Xu,Zhilong Yang,Yougui Yu,Hao Wu,Qing Zheng
We carried out thorough cyclic voltammetric (CV) studies to evaluate the intermolecular interactions between the electrochemical label and the liquor compounds. In the cyclic voltammograms, both the anodic and cathodic peak potential of FcCH2OH were positively shifted, resulting from the formation of hydrogen bonding between FcCH2OH and C2H5OH. Only the anodic peak potential of FcCH2OH was positively shifted, resulting from the formation of ion-pair between the oxidized form (Fc+CH2OH) and the negatively charged carboxylate (RCOO−). Combining cyclic voltammetry and gas chromatography, the result shows an evident correlation between peak potential and the content of the negatively charged ions present in the liquor (e.g., 1 mM sodium acetate with the potential shift of +40 ± 5 mV; 1 mM sodium citrate with the potential shift of +38 ± 4 mV). Further, a fast approach (total scanning time: 56 s), which is complementary to the conventional chromatographic and mass spectrographic characterizations, has been developed for differentiating aging times (1, 2, 3, 4, 5 and 10 years) of typical Chinese liquors.
研究领域:
分析化学
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食品科学
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DOI
高影响因子
JOURNAL OF ANALYTICAL CHEMISTRY
·
2018
·Vol. 73
·期 8
·817-823
·
IF 0.971
Hu Q. Q.,Gao H.,Wang Y. M.,Ma W.,Sun D. M.
Abstract The poly(L-arginine)–graphene modified glassy carbon electrode ( GCE ) was fabricated and the electrochemical behavior of carmine and amaranth on this electrode was studied by cyclic voltammetric method. Compared with poly(L-arginine)/GCE and GCE, the poly(L-arginine)–graphene modified GCE improved the sensitivity for the determination of carmine and amaranth. The experimental results indicated that the oxidation peaks of carmine and amaranth were separated at 121 mV in phosphate buffer solution at pH 2.5. The linear range for the simultaneous determination of carmine and amaranth were 7.5 × 10 –7 –7.5 × 10 –5 M. The detection limits were 7 × 10 –8 M for carmine and 2.5 × 10 –7 M for amaranth. The method has been applied to the simultaneous determination of carmine and amaranth in drinks with satisfactory results.
研究领域:
分析化学
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食品科学
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电化学
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DOI
高影响因子
Analytical Methods
·
2013
·Vol. 5
·期 20
·5823-5829
·
IF 1.855
Xinying Ma,Mingyong Chao
Herein, a poly(L-phenylalanine) modified glassy carbon electrode (PLPA/GCE) was fabricated by electrochemical polymerization and a convenient method for the determination of maltol in food products was developed using the fabricated PLPA/GCE. The electrochemical behavior of maltol at the modified electrode was studied by cyclic voltammetry. Experimental results show that the modified electrode exhibits excellent electrocatalytic activity towards the electrochemical oxidation of maltol and the oxidation is a one-proton–one-electron process. In pH 8.0 phosphate buffer solution, the oxidation peak current obtained by cyclic voltammetry is linearly proportional to the concentration of maltol in the range of 8.0 × 10−7 to 5.00 × 10−4 mol L−1 with a limit of detection of 9.5 × 10−8 mol L−1. The stability and reproducibility of the fabricated electrode was evaluated and the performance of the proposed method was validated in terms of linearity (r = 0.9989), recovery (95.2–101.4%), reproducibility (RSD < 3.7%, n = 6) and robustness. The applicability of the developed method has been successfully demonstrated by the determination of maltol in a variety of food products such as cake, beer and red wine.
研究领域:
分析化学
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食品科学
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电化学传感
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生物医学工程
·
食品安全检测
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2019
·
IF 7.467
Weiji Dai,Tao Lu,Ye Pan
Efficient oxygen evolution reaction catalysts based on earth-abundant and low-cost elements are urgently required for water splitting devices and metal-air batteries . Herein, for the first time we report a novel and promising MO x (M = Mn, Fe, Co and Ni) nanosheets catalyst for oxygen evolution reaction based on the MnFeCoNi high entropy alloy . By an electrochemical cyclic voltammetry scan activation, the MO x nanosheets can grow directly on the MnFeCoNi high entropy alloy particle surfaces forming a core-shell structure. The core-shell structure exhibits a low overpotential of 302 mV to achieve current density of 10 mA cm −2 , a small Tafel slope of 83.7 mV dec −1 and exceptional long-term stability of electrolysis for over 20 h in 1 M KOH alkaline solution, which is comparable to the state-of-the-art oxygen evolution reaction electrocatalyst RuO 2 . We make an investigation of the MnFeCoNi high entropy alloy before and after cyclic voltammetry scan activation on their morphologies, chemical states and elements composition to understand the materials evolution. The present work not only provides a promising electrocatalyst but also broadens the application areas of high entropy alloys.
研究领域:
材料科学
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电化学
·
能源化学
·
纳米科技
·
催化化学
✓ 已验证
DOI
高影响因子
Current Analytical Chemistry
·
2024
·Vol. 21
·期 7
·877-883
·
IF 1.7
Yong Zhang,Qianmin Cong,Chenxu Feng,Zhengyu Cai,Lizhai Pei
BackgroundCyanide is a toxic anion and may be discarded into the water environment, which is a serious threat to human beings and the environment. Hence, it is essential to explore a facile, sensitive method for cyanide detection. Polyaniline/Cu-vanadate nanobelts serve as electrode materials for sensitive cyanide determination.MethodsPolyaniline/Cu-vanadate nanobelts were obtained by a simple route using polyaniline, Cu-vanadate nanobelts. The polyaniline/Cu-vanadate nanobelts were measured via electron microscopy, diffraction, infrared spectrum, and electrochemical methods.ResultsAmorphous polyaniline nanoparticles with a particle size of about 100 nm were attached firmly to the surface of Cu-vanadate nanobelts. Electrochemical sensing properties for cyanide detection were analyzed using a cyclic voltammetry technique using the nanobelts-modified electrode. The cyclic voltammograms (CV) peaks centered at +0.64 V and +0.54 V were observed using the polyaniline/Cu-vanadate nanobelts in 0.1 M KCl solution with 2 mM cyanide. The proposed composite nanobelt-modified electrode possessed the detection range and detection limit of 0.001-2 mM and 0.22 μM, respectively.ConclusionPolyaniline greatly enhances the electro-catalytic performance of the Cu-vanadate nanobelt-modified electrode for cyanide detection.
研究领域:
分析化学
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环境监测
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电化学传感器
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纳米材料
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毒物检测
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Ke Zhang,Xu Zhao,Sihan Chen,Liping Chang,Jiancheng Wang,Weiren Bao,Hui Wang
In chemical cycles to produce hydrogen , the H 2 S splitting cycle and the sulfur-iodine (S I) water splitting cycle both share the Bunsen reaction and HI decomposition. Therefore, they have to overcome the same challenges in the technology development, one of them being the complex and difficult separations of the mixed hydroiodic acid and sulfuric acid solution after the Bunsen reaction. To avoid the separations, this paper studies the electrolysis of the HI/H 2 SO 4 /H 2 O/toluene mixture, focusing on the electrochemical characterization of the Pt electrode by using linear sweep voltammetry (LSV) and cyclic voltammetry (CV). The results show that hydrogen is identified from the gas generated from the cathode in electrolysis. Iodide oxidation is the main reaction in the anode chamber and no significant side reactions are observed. Iodine deposition on the anode surface increases the resistance to iodide diffusion to the anode. However, it can be mitigated by adding toluene in or applying stirring to the anolyte HI/H 2 SO 4 solution. The Pt cathode and sulfuric acid catholyte also work stably.
研究领域:
化学工程
·
电化学
·
可再生能源
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Yanru Fan,Bingxu Feng,Yu Huang,Xiaoquan Lu
In this paper, the interface between two immiscible electrolyte solutions (ITIES) is adopted as the bionic interface model to investigate the interfacial electron transfer (ET) process of levodopa by using thin-layer cyclic voltammetry. Three zinc porphyrins with a systematic variation in structure are used as the reactants in the organic phase for the supply of varied overall driving forces at the ITIES. The consecutive two-step ET reactions between levodopa and three zinc porphyrins with the corresponding ET rate constants are evaluated precisely. The relationship between the interfacial ET rate constants and the overall driving force are also studied. It is found that the ET kinetics of the bimolecular reactions at the ITIES obeys the Marcus theory in a wide potential region. The results of this work will assist in our understanding of the interfacial electron-transfer process of levodopa in vivo.
研究领域:
生物医学工程
·
分子药理学
·
电化学
·
神经化学
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药物代谢
·
生物物理化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2011
·Vol. 36
·期 13
·7374-7380
·
IF 4.057
Wei Wang,Qiang Zhao,Jinxiang Dong,Jinping Li
A novel silver oxides oxygen evolving catalyst (Ag-OEC) for hydrogen production by water splitting was formed in situ on an indium tin oxide anode, in a near-neutral potassium tetraborate (K 2 B 4 O 7 ) electrolyte. The catalyst exhibited high activity and low overpotential for O 2 evolution under mild conditions. The main functional composition of the catalyst was a redox couple of Ag 2 O/AgO. Catalytic activity during oxygen evolution was evaluated by cyclic voltammetry and Tafel plot. The effects of the concentration, temperature, and pH of K 2 B 4 O 7 solution on the catalyst, and the Faradaic efficiency of the oxygen evolving reaction were examined. The results show that the Ag-OEC exhibits excellent oxygen evolution properties, with an oxygen evolving overpotential of 318 mV at a current density of 1 mA/cm 2 .
研究领域:
电催化
·
能源化学
·
材料科学
·
物理化学
·
可持续能源
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DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Lin Hu,Xiaoqin Zhou,Jinqing Li,Tongtong Bai,Juan Tang,Tao Zhou,Qujin Cui
In this study, we used ferrocene/graphene to modify a glassy carbon electrode, which was fixed with an appropriate amount of Nafion solution. The -C-O-C- and -COOH functional groups were detected in the ferrocene/graphene composite using IR spectroscopy, which indicated that graphene was oxidized to graphene oxide, making it more hydrophilic, dispersible and compatible with polymers, thus increasing the chloromycetin detection rate. A scan rate of 0.05 V/s is ideal. The optimal conditions for chloromycetin detection were found using Cyclic voltammetry (CV): a scan rate of 0.05 V/s, pH 6.47, and 0.1 mol/L PBS buffer solution. Differential pulse voltammetry(DPV) shows that the concentrations of chloromycetin are 2×10 -6 - 3.2×10 -5 mol/L, and there is a good linear relationship between the peak current and the concentration: I pa (μA)=2.44772 c(μmol/L) -46.14375, r = 0.993; the detection limit is 4.5×10 -8 mol/L. This modified electrode has good stability, repeatability and operability and can be applied to detect actual samples.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Youqin Lu,Min Wang,Cunguang Yuan,Jinsheng Zhao,Jianfeng Yu
Cyclic voltammetry (CV) was used to fabricate carbon supported Pt-Cu alloy (Pt-Cu/C) for oxygen reduction reaction (ORR) at ambient temperature. A flowerlike structure of Pt-Cu nanoparticles were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy was used to confirm the surface chemical composition and metallic state. And, electrochemical measurements such as CV, rotating disk electrode, rotating ring-disk and electrochemical impedance spectroscopy were applied to obtain the kinetic constants and the reaction mechanisms of the ORR. Compared with Pt/C, Cu/C, Pt-Cu/C exhibits the highest efficient catalytic activity for ORR, as evidenced by the highest current densities of the polarization curves, lowest onset oxidation potential and charge transfer impedance. The average electron transfer number and hydrogen peroxide calculated from RRDE are about 3.87 and 6.71%, respectively. These results show that the synthesized Pt-Cu/C has excellent electrocatalytic activity and the ORR is a four-electron dominant reduction pathway.
研究领域:
电化学
·
纳米材料科学
·
催化化学
·
能源材料
·
电分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）