ELECTROCHIMICA ACTA
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2015
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IF 4.504
Mingshu Xiao,Yanping Tian,Yuhua Yan,Kai Feng,Yuqing Miao
In order to lower the energy barrier and improve the energy efficiency for hydrogen production by splitting water, highly efficient OER catalysts are required. Here, we report the electrodeposition of Ni(OH) 2 /NiOOH in the presence of urea showing the improved electrocatalysis for the hydrogen production in KOH electrolyte. By potential scanning, the Ni(OH) 2 colloid in alkali solution was transformed into the deposited Ni(OH) 2 /NiOOH. The presence of urea facilitates to deposit Ni(OH) 2 /NiOOH with higher electron transfer than the absence of urea, leading to a higher electrocatalytic OER. As supporting electrolyte , KOH exhibits better performance on the electrodeposition of Ni(OH) 2 /NiOOH and their OER electrocatalysis than NaOH. The work shows the potential application using cheap, non-precious metal-based electrocatalysts to overcome the well-known bottlenecks limiting power density of hydrogen fuel cell and energy efficiency of splitting water.
研究领域:
电化学
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催化材料
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
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2023
·
IF 2.7
Zhongying Fang,Xiaolong Liang,Lehui Lu,Wei Chen
The electrocatalytic oxidation of urea (EOU) is an important half-reaction in water splitting, urea fuel cells, and urea wastewater treatment. The anions of nickel-based catalysts can be leached severely in the oxidation potential range. Therefore, the influence of anion on the electrocatalytic performance of Ni(OH) 2 /NiOOH for urea oxidation has not been systematically studied. The present experimental results show that the structure reconstruction of catalyst is a complicated process, specifically including deep penetration by alkaline electrolyte, leaching-induced oxidation by phosphorus or sulfur anions, transformation or cracking of the original structure, and formation of an amorphous layer on the surface. The reconstructed NF-NiP x -R or NF-NiS x -R has a three-layer core-shell structure, with a nickel foam skeleton in the innermost layer, an amorphous NiP x or NiS x layer in the middle layer, the outermost layer of oxygen-containing anion (PO x or SO x ) coordinated Ni(OH) 2 . In the prepared catalyst, the Ni(OH) 2 /NiOOH redox is the real catalytic species for the urea oxidation. It is found that the oxygen-containing anion can enhance the catalytic performance of the Ni(OH) 2 /NiOOH redox, and PO x anion has the best enhancing effect. It is found that the urea molecules are oxidized on the electrocatalyst surface mainly through an indirect pathway.
研究领域:
电化学
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催化材料
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2021
·
IF 3.995
Shaohua Wang,Ping Yang,Xiangfei Sun,Lina Feng,Congcong Jin,Menglei Ren,Honglong Xing,Jianjun Shi
Because of their low synthesis cost, large specific surface area, and good energy storage performance, microporous metal-based composites have been widely used in supercapacitors and the hydrogen evolution reaction (HER). Flower-like Ni foam@ (@, coating) NCo 2 O 4 @Ni(OH) 2 /NiOOH (NF@NCO@NOH) composites were synthesized through a simple solvent-controlled method and following an electrochemical deposition process. The as-synthesized composites benefit from high specific area, a hierarchical porous structure, and the synergistic effect of Ni and Co, showing a high area-specific capacitance of 23.75 F cm −2 at a continuous current of 5 mA cm −2 . The assembled asymmetric supercapacitor exhibits an energy density of 125 Wh kg −1 at a power density of 6.24 kW kg −1 . Furthermore, 84.1% of the capacity was retained after 10,000 cycles, suggesting the sample has excellent electrochemical stability. Moreover, an overpotential of 162 mV at a current density of 10 mA cm −2 and a Tafel slope of 95 mV dec −1 were obtained in the HER measurement, indicating that the as-synthesized flower-like electrode material possesses potential applications in the HER.
研究领域:
材料科学
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能源存储与转换
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产品关联
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Yuexiang Li,Junliang Liu,Shuqi Li,Shaoqin Peng
Hydrogen production through electrochemical water splitting (EWS) presents a viable solution for addressing the fossil energy crisis. However, the commercial viability of this approach is impeded by the sluggish kinetics of the oxygen evolution reaction (OER). It is urgently needed to develop efficient, stable, and cost-effective OER electrocatalysts. Herein, we comprehensively design and investigate a phosphate ion and Fe3+ codecorating Ni(OH)2/NiOOH electrocatalyst (Pi-Fe:NiOH) for OER. This codecoration induces multiple synergistic effects, which include an increase in the interlayer water content for the internal OER, altering the OER mechanism, facilitating proton transport across the layers, and improving the stability of Pi-Fe:NiOH. Consequently, Pi-Fe:NiOH exhibits a high OER activity with overpotentials of 118 ± 1 and 222 ± 4 mV at current densities of 10 and 100 mA cm–2, respectively. More impressively, it maintains stable operation at a high current density of around 300 mA cm–2 for at least 500 h, much better than the Ni(OH)2/NiOOH electrocatalyst (NiOH) for less than 6 h at a current density below 200 mA cm–2. These findings offer insights for the design of anion–cation codoped hydroxide eletrocatalysts, paving a way for the development of efficient and stable OER electrocatalysts.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Micro & Nano Letters
·
2019
·Vol. 14
·期 7
·749-752
·
IF 0.975
Li Hong Qian,Xiao Cai Liang,Hua lan Zhou
The Ni(OH) 2 /NiOOH nanoparticles (NPs) electrodeposited on a glassy carbon electrode (GCE) in Ni(NO 3 ) 2 and NH 3 ·H 2 O aqueous solution for the electrode materials. Then the nickel hydroxide/oxyhydroxide acetate was formed in acetate solution. The effects of deposition conditions such as the concentration of Ni(NO 3 ) 2 solution, the number of sedimentary cycles, the concentration of acetate in the soaking liquid and the soaking time are discussed in detail. The electrochemical properties of the material have been investigated by cyclic voltammetry, Tafel curve, EIS and amperometric i–t curve techniques. The result displays excellent electrocatalytic activity towards the electrocatalytic oxidation of urea in alkaline solution. Furthermore, the modified electrode for oxidation reaction has the advantages of simple preparation, good electrochemical properties and stabilisation.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2026
·
IF 5.2
Lei Jiang,Chunli Mao,Gaojie Cheng,Hongbo Yang,Jiawen Yin,Qinghui Jin
An integrated three-electrode non-enzymatic urea sensor is developed. • The sensor exhibits a wide linear range (1–200 mg/L) and a fast response (10.8 s). • Detection potential dynamically regulates the contributions of the two urea oxidation pathways. Rapid and accurate monitoring of urea concentration in swimming pool water is critical for protecting swimmers' health and optimizing water quality management. However, traditional techniques are either expensive or operationally complex, whereas enzyme-based sensors suffer from enzyme deactivation, limiting their applicability for online monitoring. In this paper, a nickel hydroxide/nickel oxyhydroxide (Ni(OH) 2 /NiOOH) nanonetwork electrochemical sensor for non-enzymatic urea detection is proposed, which is mass-produced on a platinum electrode using microelectromechanical systems (MEMS). The electrode was activated and optimized via cyclic voltammetry by varying the scan rate. The sensor demonstrates a high sensitivity of 1.43 μA/(mg·L −1 ·cm 2 ), a wide detection range of 1–200 mg/L, a fast response time (<12 s), good repeatability with a relative standard deviation (RSD) of 1.24%, and an excellent linearity ( R 2 = 0.9988). In addition, the proposed sensor exhibits excellent anti-interference performance toward coexisting species such as creatinine, uric acid, residual chlorine, and lactic acid. Practical applications in swimming pool water samples yielded recovery rates of 92.5–100.4%, validating the sensor's robustness. Two distinct oxidation mechanisms for urea on the electrode were observed by electrochemical impedance spectroscopy (EIS). The direct pathway was further found to be potential-tunable, with its charge-transfer resistance decreasing by 35.6% upon raising the working potential from 0.45 V to 0.50 V. This work offers a promising route toward non-enzymatic urea sensors for swimming pool water monitoring. Download: Download high-res image (140KB) Download: Download full-size image
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2026
·
IF 9.1
Xiao Zhang,XuChen Guo,Xueying Zhang,Yunyi Ge,Feng Shen,Boxiong Shen
Integrating phase-change absorption with catalytic desorption offers a promising strategy for low-energy amine-based CO 2 capture; however, catalytic desorption of the CO 2 -rich phase in phase-change absorbents remains challenging because the highly enriched ionic products hinder product activation, proton transfer, and interfacial mass transport. Herein, a Ni(OH) 2 /NiOOH catalyst with an open layered nanosheet structure, abundant surface hydroxyl groups, and interlayer water was developed and applied to both our previously reported phase-change absorbent and a 30 wt% aqueous MEA system. The catalyst increased the maximum CO 2 desorption rate by 40% in the phase-change system and by 43% in the aqueous MEA system, while reducing the relative heat duty by 32.9% in the phase-change system, demonstrating efficient catalytic desorption performance and good cross-system applicability. Structural and mechanistic analyses reveal that the open nanosheet architecture shortens diffusion pathways and improves active-site accessibility, while surface hydroxyl groups and interlayer water construct a hydrogen-bond network for proton migration. Meanwhile, the Ni 2+ /Ni 3+ interface promotes interfacial electron transfer, enhances carbamate polarization, and weakens the C N bond. These effects synergistically facilitate carbamate decomposition and protonated amine deprotonation, providing new insights into catalyst design for low-energy CO 2 capture.
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产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Jiang Xiaoyi,Ke Le,Zhao Kai,Yan Xiaoyu,Wang Hongbo,Cao Xiaojuan,Liu Yuchen,Li Lingjiao,Sun Yifei,Wang Zhiping,Dang Dai,Yan Ning
Electrochemical carbon dioxide reduction reaction using sustainable energy is a promising approach of synthesizing chemicals and fuels, yet is highly energy intensive. The oxygen evolution reaction is particularly problematic, which is kinetically sluggish and causes anodic carbon loss. In this context, we couple CO 2 electrolysis with hydrogen oxidation reaction in a single electrochemical cell. A Ni(OH) 2 /NiOOH mediator is used to fully suppress the anodic carbon loss and hydrogen oxidation catalyst poisoning by migrated reaction products. This cell is highly flexible in producing either gaseous (CO) or soluble (formate) products with high selectivity (up to 95.3%) and stability (>100 h) at voltages below 0.9 V (50 mA cm −2 ). Importantly, thanks to the “transferred” oxygen evolution reaction to a water electrolyzer with thermodynamically and kinetically favored reaction conditions, the total polarization loss and energy consumption of our H 2 -integrated CO 2 reduction reaction, including those for hydrogen generation, are reduced up to 22% and 42%, respectively. This work demonstrates the opportunity of combining CO 2 electrolysis with the hydrogen economy, paving the way to the possible integration of various emerging energy conversion and storage approaches for improved energy/cost effectiveness.
研究领域:
电化学
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能源转换与存储
·
可持续能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）