Enabling nickel ferrocyanide nanoparticles for high-performance ammonium ion storage
《化学科学与工程前沿(英文)》
2023年
第17卷
第2期
页码 226-235
doi:
10.1007/s11705-022-2198-3
摘要:
Prussian blue and its analogs are extensively investigated as a cathode for ammonium-ion batteries. However, they often suffer from poor electronic conductivity. Here, we report a Ni2Fe(CN)6/multiwalled carbon nanotube composite electrode material, which is prepared using a simple coprecipitation approach. The obtained material consists of nanoparticles with sizes 30–50 nm and the multiwalled carbon nanotube embedded in it. The existence of multiwalled carbon nanotube ensures that the Ni2Fe(CN)6/multiwalled carbon nanotube composite shows excellent electrochemical performance, achieving a discharge capacity of 55.1 mAh·g–1 at 1 C and 43.2 mAh·g–1 even at 15 C. An increase in the ammonium-ion diffusion coefficient and ionic/electron conductivity based on kinetic investigations accounts for their high performance. Furthermore, detailed ex situ characterizations demonstrate that Ni2Fe(CN)6/multiwalled carbon nanotube composite offers three advantages: negligible lattice expansion during cycling, stable structure, and the reversible redox couple. Therefore, the Ni2Fe(CN)6/multiwalled carbon nanotube composite presents a long cycling life and high rate capacity. Finally, our study reports a desirable material for ammonium-ion batteries and provides a practical approach for improving the electrochemical performance of Prussian blue and its analogs.
关键词:
nickel ferrocyanides
NH4+
electrochemistry
Prussian blue
aqueous ammonium ion batteries
Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition
《能源前沿(英文)》
doi:
10.1007/s11708-023-0898-0
摘要:
Electrocatalytic CO2 reduction (ECR) offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO2 as the feedstock. However, the lack of cost-effective electrocatalysts with better performances has seriously hindered its application. Herein, a one-step co-electrodeposition method was used to introduce Zn, a metal with weak *CO binding energy, into Cu to form Cu/Zn intermetallic catalysts (Cu/Zn IMCs). It was shown that, using an H-cell, the high Faradaic efficiency of C2+ hydrocarbons/alcohols () could be achieved in ECR by adjusting the surface metal components and the applied potential. In suitable conditions, FEC2+ and current density could be as high as 75% and 40 mA/cm2, respectively. Compared with the Cu catalyst, the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area (ECSA), which accelerate the reaction. Moreover, the *CO formed on Zn sites can move to Cu sites due to its weak binding with *CO, and thus enhance the C–C coupling on the Cu surface to form C2+ products.
关键词:
carbon dioxide electroreduction
electrochemistry
co-electrodeposition
intermetallic catalysts
value-added chemicals
Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes
Zhenlian Qi, Jinna Zhang, Shijie You
《环境科学与工程前沿(英文)》
2018年
第12卷
第3期
doi:
10.1007/s11783-018-1034-y
摘要:
We in our previous study reported the wireless electrocoagulation (WEC) based on bipolar electrochemistry for water purification. One of the most important advantages of WEC is the omission of ohmic connection between bipolar electrode (BPE) and power supply, and thus the electrochemical reactions on BPE are driven by electric field in solution induced by driving electrodes. In this study, the impact of placement angle of bipolar aluminum electrode on WEC was investigated to provide a detailed analysis on the correlations between the bipolar electrode placement angle and bipolar electrocoagulation reactions. The results showed that the WEC cell with a horizontal BPE placed at 0° produced the maximum dissolved aluminum coagulant, accounting for 71.6 % higher than that with a vertical one placed at 90°. Moreover, the finite element simulations of current and potential distribution were carried out along the surface of BPE at different placement angles, revealing the mechanism of different BPE placement angles on aluminum dissolution rates in WEC system.
关键词:
Bipolar electrochemistry
Wireless electrocoagulation
Placement angle
nanoparticle decorated N-doped carbons derived from a cobalt covalent organic framework for oxygen electrochemistry
《化学科学与工程前沿(英文)》
2021年
第15卷
第6期
页码 1550-1560
doi:
10.1007/s11705-021-2104-4
摘要:
The low cost and highly efficient construction of electrocatalysts has attracted significant attention owing to the use of clean and sustainable energy technologies. In this work, cobalt nanoparticle decorated N-doped carbons (Co@NC) are synthesized by the pyrolysis of a cobalt covalent organic framework under an inert atmosphere. The Co@NC demonstrates improved electrocatalytic capabilities compared to N-doped carbon without the addition of Co nanoparticles, indicating the important role of cobalt. The well-dispersed active sites (Co-Nx) and the synergistic effect between the carbon matrix and Co nanoparticles greatly enhance the electrocatalytic activity for the oxygen reduction reaction. In addition, the Co content has a significant effect on the catalytic activity. The resulting Co@NC-0.86 exhibits a superb electrocatalytic activity for the oxygen reduction reaction in an alkaline electrolyte in terms of the onset potential (0.90 V), half-wave potential (0.80 V) and the limiting current density (4.84 mA·cm–2), and a high selectivity, as well as a strong methanol tolerance and superior durability, these results are comparable to those of the Pt/C catalyst. Furthermore, the superior bifunctional activity of Co@NC-0.86 was also confirmed in a home-built Zn-air battery, signifying the possibility for application in electrode materials and in current energy conversion and storage devices.
关键词:
cobalt embedment
N-doped carbons
covalent organic framework
oxygen reduction
Zn-air battery
Metal phosphonate-derived cobalt/nickel phosphide@N-doped carbon hybrids as efficient bifunctional oxygen electrodes for Zn−air batteries
《化学科学与工程前沿(英文)》
2022年
第16卷
第9期
页码 1367-1376
doi:
10.1007/s11705-022-2153-3
摘要:
The exploration of efficient bifunctional electrocatalysts for oxygen reduction reaction and oxygen evolution reaction is pivotal for the development of rechargeable metal–air batteries. Transition metal phosphides are emerging as promising catalyst candidates because of their superb activity and low cost. Herein, a novel metal phosphonate-derived cobalt/nickel phosphide@N-doped carbon hybrid was developed by a carbothermal reduction of cobalt/nickel phosphonate hybrids with different Co/Ni molar ratios. The metal phosphonate derivation method achieved an intimately coupled interaction between metal phosphides and a heteroatom-doped carbon substrate. The resultant Co2P/Ni3P@NC-0.2 enables an impressive electrocatalytic oxygen reduction reaction activity, comparable with those of state-of-the-art Pt/C catalysts in terms of onset potential (0.88 V), 4e‒ selectivity, methanol tolerance, and long-term durability. Moreover, remarkable oxygen evolution reaction activity was also observed in alkaline conditions. The high activity is ascribed to the N-doping, abundant accessible catalytic active sites, and the synergistic effect among the components. This work not only describes a high-efficiency electrocatalyst for both oxygen reduction reaction and oxygen evolution reaction, but also highlights the application of metal phosphonate hybrids in fabricating metal phosphides with tunable structures, which is of great significance in the energy conversion field.
关键词:
metal phosphonate
cobalt/nickel phosphide
N-doped carbon
oxygen electrochemistry
Zn−air battery
Probing the redox process of
Rui Lu, Wei Chen, Wen-Wei Li, Guo-Ping Sheng, Lian-Jun Wang, Han-Qing Yu
《环境科学与工程前沿(英文)》
2017年
第11卷
第1期
doi:
10.1007/s11783-017-0905-y
摘要:
Fluorescece spectroelectrochemistry is used to probe redox process of benzoquinone. The benzoquinone reduction state has a lower fluorescence quantum efficiency. CVF and DCVF can reveal more information about benzoquinone redox reactions. This method can analyze compounds with fluorescence and electrochemical activities. Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic volta- fluorescence spectrometry (CVF) and derivative cyclic volta- fluorescence spectrometry (DCVF), to determine the electrochemical properties of -benzoquinone in dimethyl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction of -benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of -benzoquinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction of -benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of -benzoquinone and other natural organic compounds.
关键词:
p-Benzoquinone
Electrochemistry
Fluorescence
Spectroelectrochemistry
Derivative cyclic volta fluorescence
Electrochemistry during efficient copper recovery from complex electronic waste using ammonia based solutions
Zhi Sun, Hongbin Cao, Prakash Venkatesan, Wei Jin, Yanping Xiao, Jilt Sietsma, Yongxiang Yang
《化学科学与工程前沿(英文)》
2017年
第11卷
第3期
页码 308-316
doi:
10.1007/s11705-016-1587-x
摘要:
Leaching selectivity during metal recovery from complex electronic waste using a hydrochemical process is always one of the generic issues. It was recently improved by using ammonia-based leaching process, specifically for electronic waste enriched with copper. This research proposes electrodeposition as the subsequent approach to effectively recover copper from the solutions after selective leaching of the electronic waste and focuses on recognising the electrochemical features of copper recovery. The electrochemical reactions were investigated by considering the effects of copper concentration, scan rate and ammonium salts. The diffusion coefficient, charge transfer coefficient and heterogeneous reaction constant of the electrodeposition process were evaluated in accordance with different solution conditions. The results have shown that electrochemical recovery of copper from ammonia-based solution under the conditions of selective electronic waste treatment is charge transfer controlled and provide bases to correlate the kinetic parameters with further optimisation of the selective recovery of metals from electronic waste.
关键词:
copper recovery
electronic waste
end-of-life products
selective leaching
electrodeposition
标题
作者
时间
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Research progress in tribo-electrochemistry and tribo-electrochemical polishing
ZHAI Wenjie
期刊论文
Study on tribological and electrochemistry properties of metal materials in H2O2 solutions
Chengqing YUAN, Li YU, Jian LI, Xinping YAN
期刊论文
Enabling nickel ferrocyanide nanoparticles for high-performance ammonium ion storage
期刊论文
Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition
期刊论文
Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes
Zhenlian Qi, Jinna Zhang, Shijie You
期刊论文
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郑文天, 尤世界, 姚远, 任南琪, 丁彬, 李方, 刘艳彪
期刊论文
nanoparticle decorated N-doped carbons derived from a cobalt covalent organic framework for oxygen electrochemistry
期刊论文
Metal phosphonate-derived cobalt/nickel phosphide@N-doped carbon hybrids as efficient bifunctional oxygen electrodes for Zn−air batteries
期刊论文
Probing the redox process of
Rui Lu, Wei Chen, Wen-Wei Li, Guo-Ping Sheng, Lian-Jun Wang, Han-Qing Yu
期刊论文
Electrochemistry during efficient copper recovery from complex electronic waste using ammonia based solutions
Zhi Sun, Hongbin Cao, Prakash Venkatesan, Wei Jin, Yanping Xiao, Jilt Sietsma, Yongxiang Yang
期刊论文
电化学微反应技术的工程研究进展——一种新型有机化合物电合成方法
郑思源, 闫俊妤, 王凯
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Two-dimensional self-assembly of melem and melemium cations at pH-controlled aqueous solution–Au(111) interfaces under electrochemical control
Shinobu Uemura,Kenki Sakata,Masashi Aono,Yusuke Nakamura,Masashi Kunitake
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微生物电合成中链脂肪酸
褚娜, 郝雯, 吴清莲, 梁勤军, 蒋永, 梁鹏, 任智勇, 曾建雄
期刊论文