Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Ping Zhang,Dan Zou,Chunhua Dong,Feiping Zhao,Weichun Yang,Mengying Si,Zhihui Yang
Heavy metal polluted soil remediation is a global concern. Therefore, it is urgently needed to develop new ways for soil remediation . Although the electrochemical method is a simple, efficient, and promising process, the reaction mechanism of arsenic (As) in contaminated soil treated by the electrochemical method is rarely noticed. Herein, electrochemical techniques were developed for As removal from contaminated soil, which can be effectively achieved by using a Fe sacrificial anode to form Fe 3+ species and by combining manganese oxide in soils for remediation. The results showed that the As was changed from an unstable to a stable state, and As pollutions were effectively removed by this electrochemical method. Further, the dissolution kinetics of Fe and Mn oxides , arsenic reaction kinetics and the phase transformation process during the remediation process were investigated by cyclic voltammetry (CV) methods. From the simulation experiments, it was found that As(III) should be oxidized by Mn 4+ and Fe 3+ to form As(V), and As(V) was the main reactant with Fe and Mn oxides for As removal. Consequently, the current work may provide a new insight into solve As contamination in soil, and provide some new insights into the interaction mechanism between multiple components.
研究领域:
环境科学
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土壤修复
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2021
·Vol. 168
·期 11
·113505
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IF 4.316
Yapeng Kong,Yu Xiao,Xuemin Liang,Yuran Chen,Liqiang Wang
The availability of casting Ni–Fe alloy as inert anode for direct electro-reduction of V2O3 in molten Na3AlF6-K3AlF6-AlF3 was investigated. The electrochemical oxidation behavior of anode as well as microstructural evolutions of formed oxide scale were systematically studied. The electrochemical characterization and reaction mechanism of the cathode oxide were also investigated to evaluate the influence of alloy anode on cathodic reduction process. The in situ formed three-layered oxide scale is compact and coherent, which is composed of an outermost Fe2O3 + FeAl2O4 skin layer, a Fe2O3 middle layer and a FeAl2O4 inner layer. The skin layer has a continuous, smooth structure and shows electrochemical activity. The Fe2O3 layer with a compact structure prevents inward diffusion of electrolyte and outward migration of metal cations. The innermost FeAl2O4 layer shows a loose structure and functions as a buffer layer to improve the peeling resistance of oxide scale. With the continuous extension of polarization time, the inner FeAl2O4 layer is slowly oxidized and becomes thinner, simultaneously, the dense Fe2O3 layer becomes thicker. Ultimately, metal vanadium product with fine rod-like particles can be obtained and the oxygen content in the metal vanadium is below 0.3 mass% within electrolyzing time of 2 h. The corresponding current efficiency is around 63%.
研究领域:
冶金学
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材料科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
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2020
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IF 6.215
Jing Wang,Tong Zheng,Huiling Liu,Gang Wang,Yanxiang Zhang,Chen Cai
In this study, the electrochemical generation of ferrate (Fe(VI)) from grey cast iron anode in sodium hydroxide (NaOH) solution was utilized in situ to degrade the malodorous pollutant of ethanethiol (C 2 H 5 SH). During electrolysis, C 2 H 5 SH was oxidized by the combination of direct anodic oxidation and Fe(VI) oxidation (indirect oxidation). The direct anodic oxidation process, which played an important role in the decontamination process but was often disregarded in related studies, was investigated in detail. The electrochemical generation of Fe(VI) was investigated, and the maximum current efficiency of Fe(VI) generation was obtained in 14 M NaOH solution. The voltammetry studies of the grey cast iron anode in NaOH solutions containing and without C 2 H 5 SH revealed that the dissolution of anode was improved in the presence of C 2 H 5 SH. A decrease in NaOH concentration increased the contribution of direct anodic oxidation but decreased the electrochemical generation of Fe(VI). C 2 H 5 SH was degraded on the grey cast iron anode at a higher rate in less concentrated NaOH solution ( k = 4.15 × 10 −2 min −1 in 2 M NaOH solution), which could be ascribed to the enhancement in direct anodic oxidation as well as in the oxidizing power of Fe(VI). Higher current density promoted the degradation rate of C 2 H 5 SH in both direct and indirect oxidation processes, but it also decreased the current efficiency due to the improvement of the side reactions. Additionally, the in-situ and on-line applications of the electrochemical generated Fe(VI) in recent studies were presented and discussed. This study provides a comprehensive understanding of C 2 H 5 SH oxidation on grey cast iron anode, and offers a feasible electrochemical scrubbing approach using grey cast iron as the anode for C 2 H 5 SH odors control.
研究领域:
环境科学
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电化学工程
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 52
·2407715
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IF 13
Chang Li,Xinyu Guo,Wenjun Deng,Na Shen,Yi Zhou,Yan Chen,Rui Li
Aqueous iron-ion batteries with reversible storage of Fe 2+ have undergone rapid development in recent years. Consistently throughout these studies, metallic iron is selected as the anode material. However, the large overpotential (250 mV) associated with the plating/stripping process of iron in aqueous solutions leads to unsatisfactory energy efficiency of the battery, although high capacity and Coulomb efficiency can be achieved. Herein, an iron-free anode material, 9,10-anthraquinone (AQ) is proposed in aqueous iron-ion batteries, which shows a low reaction potential and minimal polarization during storing iron ions. The organic anode exhibits favorable specific capacity of 106 mAh g −1 at 0.5 A g −1 and excellent cycling stability (92.6% retention after 500 cycles). In addition, an aqueous full iron-ion battery is constructed using AQ as the anode and 9,10-phenanthraquinone (PQ) as the cathode. The full battery demonstrates an enhanced energy efficiency of 72%, which is 206% higher than that of metal iron anode, and shows excellent cycling stability and Coulombic efficiency. This work provides a viable route to overcome the high polarization of metallic iron anode and promote the development of aqueous iron-ion batteries.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2020
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IF 7.183
Xiaohui Li,Lifen Liu,Tong Liu,Danfeng Zhang,Changwei An,Fenglin Yang
Cathode membranes can provide innovative solutions for membrane-fouling mitigation and filtration performance enhancement, in combination with electric field in a new electrochemical system. In this research, a novel polyvinylidene fluoride/stainless steel/polypyrrole (PVDF/SS/PPy) cathode membrane was prepared via in situ flow-through electro-polymerization method. The PVDF/SS/PPy membrane exhibited excellent electric catalytic activity for 2-electron ORR (oxygen reduction reaction). A battery system with PVDF/SS/PPy membrane cathode and Fe sacrificial anode was developed for in situ •OH generation. A pH range of 3.5–4.0 is preferred and the area ratio of iron anode to PVDF/SS/PPy cathode membrane was ~1:6 according to the •OH production and iron consumption results. The phenol filtration tests suggested that the PVDF/SS/PPy cathode membrane has improved selectivity for removing small refractory organic pollutant such as phenol, the removal rate increased from 54.7% to 79.3%, while flux decreased from 152 L/(m 2 ·h) to 19 L/(m 2 ·h). The results of filtrating river water and BSA indicated that the PVDF/SS/PPy cathode membrane had excellent anti-fouling performance when the foulants load matches the •OH production.
研究领域:
环境科学
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材料科学
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电化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2017
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IF 6.065
Xuhui Sun,Kexin Zu,He Liang,Lin Sun,Lingyun Zhang,Chuanyi Wang,Virender K. Sharma
Passivation of anode is a main challenge in the electrochemical synthesis of ferrate(VI) (Fe VI O 4 2− , Fe(VI)). A series of electrochemical approaches were employed including polarization curve, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) to analyze the physicochemical processes involved in electrochemical synthesis of Fe(VI) using sponge iron and cast iron anodes. The results demonstrate that the sponge iron anode achieved higher yield of Fe(VI) compared to grey cast iron anode. The optimum condition to generate Fe(VI) using sponge iron was 35–50 °C and 30 mA/cm 2 . Significantly, the sponge iron anode could generate Fe(VI) for a long duration (>10 h) under these conditions; possibly suitable for large scale synthesis of Fe(VI). The prepared Fe(VI) solution was used to treat antibiotic (sulfamethoxazole (SMX)) and pesticide (atrazine (ATZ)) in water. At a molar ratio of Fe(VI) to SMX as 20:1 in the pH range from 5.0 to 9.0, almost complete oxidative transformation of SMX could be obtained. Comparatively, oxidative transformation of ATZ was incomplete (∼70%) even when [Fe(VI)]:[ATZ] = 87 at pH 5.0–9.0. Fluorescence spectra and cytotoxicity studies suggest that the oxidative transformation products of both SMX and ATZ possess lower toxicity than the parent antibiotic and pesticide, respectively.
研究领域:
环境化学
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电化学
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水处理
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产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 19
·3472
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IF 5.719
Hongwei Tang,Mengyue Liu,Lingna Kong,Xiaoyan Wang,Yue Lei,Xige Li,Yan Hou,Kun Chang,Zhaorong Chang
In this paper, a series of Fe3O4/MoS2/NiS composite electrodes were synthesized by a simple coprecipitation method. The influence of different ratio additives (MoS2and NiS) on the performance of iron anodes for Ni-Fe batteries was systematically investigated. In this paper, the mixed alkaline solution of 6 mol/L NaOH and 0.6 mol/L LiOH was used as electrolyte, and sintered Ni(OH)2was used as counterelectrode. The experimental results show that the MoS2and NiS additives can effectively eliminate the passivation phenomena in iron electrodes, reduce the electrode polarization, and increase the reversibility capacity. As a result, the Fe3O4/MoS2/NiS composite electrodes exhibit a high specific capacity, good rate performance, and long cycling stability. Especially, the Fe3O4/MoS2(5%)/NiS (5%) electrode with a suitable ratio of additives can provide excellent electrochemical performance, with high discharge capacities of 657.9 mAh g−1, 639.8 mAh g−1, and 442.1 mAh g−1at 600 mA g−1, 1200 mA g−1, and 2400 mA g−1, respectively. This electrode also exhibits good cycling stability.Keywords:nickel-iron battery;iron anode;Fe3O4;sulfide additives
研究领域:
电化学
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材料科学
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电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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