JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Xinrui Qiang,Chao Feng,Bingzhe Jia,Han Wang,Yan Wang,Xinming Wu
The same element heterojunction structure can effectively improve the energy density of the electrodes with its unique structural properties, but the specific mechanism of heterojunction action is not clear. Based on this, in this paper, the same element heterojunction electrode constructed with FeOOH on NiFe-LDHs can reach a specific capacitance of 4.34 F cm -2 at 2 mA cm -2 . After 6000 cycles, its capacity is still maintained to 95.67% (30 mA cm -2 ). The FeOOH@NiFe-LDHs//AC flexible supercapacitor device was prepared to achieve a specific capacitance of 1.06 F cm -2 at 2 mA cm -2 . More notably, an impressive energy density of 0.47 mWh cm -2 at 1.78 mW cm -2 was achieved, which is higher than previous reported. In addition, the capacitance remains 96.3% after 3000 cycles at 50 mA cm -2 , and the electrode exhibited flexibility and outstanding bending stability. The high energy density of the electrodes in this study is attributed to the resulting Fermi energy level differences, which provide more carriers and increase the conductivity of the electrode material. This suggests that the heterojunction has obvious advantages for increasing the energy density of both flexible and non-flexible electrodes, and also provides new ideas for the application of supercapacitors in wearable electronic devices.
研究领域:
材料科学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Chengzhi Wei,Wenrui Wu,Yang Yang,Yue Yan,Hao Zhang,Xianfu Li
In this study, MoSe2 and NiFe-LDHs were synthesized on a self-supported conductive nickel foam (NF) substrate via a one-step method. Specifically, MoSe2 was grown on the nickel foam via a one-step solvothermal method to form the MoSe2/NF precursor material. Subsequently, NiFe-LDHs were deposited on the MoSe2/NF substrate through a one-step hydrothermal method, resulting in the formation of the NiFe-LDHs/MoSe2/NF composite material. We found that although both NiFe-LDHs and MoSe2 monomers have certain disadvantages, such as a tendency to agglomerate and relatively poor electrical conductivity, their combination yields an interesting “two negatives make a positive” effect. The NiFe-LDHs/MoSe2/NF composite exhibits a high specific capacitance of 6790 mF cm–2 at a current density of 2 mA cm–2, which is significantly higher than that of NiFe-LDHs (1317.6 mF cm–2) and MoSe2 (1475.2 mF cm–2). Additionally, the composite demonstrates excellent cycling stability, with a capacitance retention of 99.87% after 4000 cycles. In contrast, NiFe-LDHs/NF retains only 54.01% of its capacitance after 2000 cycles, and MoSe2/NF retains only 48.15% after the same number of cycles. The asymmetric supercapacitors (ASCs) assembled from the NiFe-LDHs/MoSe2/NF composite and activated carbon (AC) show remarkable performance. These devices have a high potential window of 0–1.55 V and achieve an extremely high energy density of 0.5558 mWh cm–2 at a power density of 1.55 mW cm–2. Moreover, they exhibit an ultrahigh capacitance retention of 99.1% after 10,000 cycles, indicating excellent cycling stability. The Coulombic efficiency of the capacitor remains at a high value of approximately 99.8% throughout the cycling process. NiFe-LDHs/MoSe2/NF and similar materials can be designed for flexible supercapacitors integrated into clothing or skin patches to power sensors. In the context of medical device designs requiring energy storage components to rapidly release substantial energy, they may also play a critical role.
研究领域:
材料科学
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能源存储
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2022
·Vol. 17
·期 16
·e202200476
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IF 4.839
Kaiqi Zhang,Hongyan Song,Zhe An,Jian Zhang,Yanru Zhu,Zhigang Chai,Xin Shu,Jing He
Graphical NiFe- LDHs/P-TCN heterojunction has been constructed with P-dopant defects and interface synergy. Moreover, Its mesoscale mechanism was elucidated among different constituent interfaces. The semiconductor based photocatalysis has become a hot spot of current research, and the key challenges are the construction of strong functional heterojunction photocatalysts, and insights on the working mechanism involved. In this work, we constructed a NiFe- LDHs/P-TCN heterojunction with P-dopant defects and interface synergy and elucidated its mesoscale mechanism among different constituent interfaces. The interface photoelectron transfer was detected by PAS, EPR and other methods, and the enhancing mechanism of the defect sites for interface electron transfer and photocatalytic activity was proposed. The interfacial electrons, photoelectric properties and photocatalytic activity are found to be positively correlated. The result is conducive for a better understanding on working mechanism of heterogeneous photocatalysts, which opened a broader research space for the rational design and construction of functional interfaces.
研究领域:
材料科学
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环境科学
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光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RARE METALS
·
2024
·
IF 9.6
Li Jia-Hong,Chen Hao,You Si-Hang,Yang Gan-Xin,Liu Peng,Gao Meng-Qi,Chen Shu-Guang,Zhang Fei-Fei
Owing to the significant potential of alkaline seawater electrolysis for converting surplus power into eco-friendly hydrogen fuel, we developed bifunctional electrodes that integrate low-crystalline NiFe LDHs and amorphous NiFe alloy on a Ni foam (NF) substrate to enhance this process. Driven by the battery-like characteristics of NiFe LDHs, an anti-corrosive and active outer layer of NiFe vac OOH continuously forms over time in the hybrid on the anode for the oxygen evolution reaction (OER), effectively mitigating powder shedding caused by corrosion induced by multiple anions in seawater. Meanwhile, the strong bond between the hybrid and the NF substrate maintains intact hybrid coatings to ensure a relatively high overall conductivity of the electrodes, significantly reducing the negative effects of structural degradation during the OER and hydrogen evolution reaction (HER), as well as the accumulation of contaminants on the electrode surfaces. In long-term tests, these bifunctional hybrid electrodes maintained stable performance, even at a high current density of 500 mA·cm −2 . The cell voltage increased by only 88 mV over 1000 h to 1.970 V during saline electrolysis and by 103 mV over 500 h to 2.062 V during seawater electrolysis. Hence, this study provides valuable insights into efficient and stable seawater electrolysis using NiFe LDHs–NiFe alloy hybrids. Graphical abstract
研究领域:
材料科学
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电化学
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可再生能源
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Dandan Li,Tan Li,Genyan Hao,Wenjun Guo,Shuai Chen,Guang Liu,Jinping Li,Qiang Zhao
A hybrid oxygen evolution catalyst, IrO 2 @single-layer NiFe layered double hydroxides (SL-NiFe LDHs), is successfully synthesized by anchoring highly dispersed IrO 2 nanoparticles to SL-NiFe LDHs nanosheets with oxygen vacancies. Typically, during the synthesis process, the functional group –NH 2 from the external anchor formamide acts as a coordination site to control the nucleation and growth of nanoparticles , which can ensure high dispersion without aggregation of IrO 2 on SL-NiFe LDHs. In addition, this reducing synthetic environment causes a large number of holes and grooves in the NiFe-LDHs nanosheets, which result in the formation of oxygen vacancies in the SL-NiFe LDHs. The loading of IrO 2 nanoparticles and the formation of oxygen vacancies endow IrO 2 @SL-NiFe LDHs with excellent performance for the oxygen evolution reaction (OER). IrO 2 @SL-NiFe LDHs nanosheets display outstanding OER performance with an overpotential of 270 mV at a current density of 10 mA cm −2 and good stability. Density functional theory (DFT) calculations indicate that the hybridization of IrO 2 and SL-NiFe LDHs accelerates the reaction step. Notably, the Ir sites at the edges are more conducive to the formation of oxygen, and the oxygen sites on SL-NiFe LDHs are more conducive to the cleavage of the O–H bond, thereby improving the OER activity. This work highlights a potential synthetic strategy that can combine nanoprecious metals with transition metals to prepare highly active electrocatalysts for efficient water oxidation reactions.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
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2017
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IF 5.715
Jie Tang,Bin Mu,Li Zong,Aiqin Wang
Magnetic attapulgite/carbon supported NiFe layered double hydroxides (APT/C@NiFe-LDHs) were fabricated based on the spent bleaching earth via a facile and green hydrothermal approach. Multiple characterizations were conducted to illustrate that NiFe-LDHs was successfully anchored on the surface of APT during the preparation process. The magnetic response and adsorption properties of as-prepared composites could be facilely controlled by varying the Ni/Fe molar ratio . As expected, the coating of NiFe-LDHs significantly increased the adsorption ability to pollutants, the resultant composites prepared at the Ni/Fe molar ratio of 1:1 exhibited excellent adsorption capacities for methylene blue , Pb(II), and chlortetracycline hydrochloride of 271.28, 180.90, and 308.21 mg/g, respectively. The high adsorption capacity of the obtained adsorbents could be ascribed to the synergetic effect of the carbon species and NiFe-LDHs. In addition, the adsorbent could be easily separated by magnetic separation technology, and exhibited a stable recyclability after six adsorption-desorption cycles. This work provided a feasible pathway to design and fabricate adsorption materials for wastewater treatment taken into account both high-performance adsorption and cost-effective way.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Lingyu Li,Zhichang Qiu,Yuanfeng Qi,Dantong Zhao,Iftikhar Ali,Chenglong Sun,Longhua Xu,Zhenjia Zheng,Chunxia Ma
Gold nanoparticles (AuNPs) have been widely used as laser desorption/ionization mass spectrometry (LDI-MS) nanomaterials for the analysis of low-molecular-weight samples. Nickel/iron-layered double hydroxides (NiFe-LDHs) nanosheets can support the anchoring of AuNPs and enhance the ability of desorption/ionization. Their hybrid nanocomposites are expected to produce synergistic effects to improve the performance of LDI-MS. In this work, a novel AuNPs/NiFe-LDHs nanomaterial was synthesized by self-assembly method and characterized based on TEM , SEM , XPS, UV-vis and FTIR-ATR. AuNPs/NiFe-LDHs assisted LDI-TOF MS exhibited higher peak intensity and lower background noise compared with conventional organic matrices. Furthermore, excellent salt and protein tolerance, good repeatability and quantification were observed when MNZ and its metabolites were detected in the range of 1–50 ng·μL −1 ( R 2 > 0.98), with LODs and LOQs of 0.5 ng·μL −1 and 1 ng·μL −1 , respectively. This nanocomposite could also be used for the analysis of some other small molecules, such as antibiotics, sugars, amino acids and pesticides, demonstrating the potential to detect a variety of environmental chemicals. Taken together, the developed method combined the advantages of two nanomaterials and can provide rapid and accurate analysis of MNZ and its metabolites in water samples, as well as some other small molecules.
研究领域:
分析化学
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环境科学
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纳米技术
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质谱分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Shifeng Li,Tiankuo Zang,Xiaoyun Yang,Min Xiao,Haibo Wang,Shuhua Yao,Zhongliang Shi
The utilization of waste melamine-formaldehyde foam to produce value-added carbon foam has been identified as a promising approach to polymer recycling. Nickel-Iron layered double hydroxides (NiFe-LDHs) and its complex oxides (NiFe 2 O 4 ) were synthesized in this study through a hydrothermal method, growing in situ on the above-mentioned carbon foam substrate. Comparative analysis revealed that CF@NiFe 2 O 4 exhibited superior removal efficiency compared to CF@NiFe-LDHs. Furthermore, arsenate adsorption on CF@NiFe-LDHs and CF@NiFe 2 O 4 conformed more to the pseudo-second-order model; meanwhile, the isothermal adsorption characteristic fitted the Langmuir isothermal model better. The negative ΔG (free energy changes, <−37.68 kJ/mol) and positive ΔH (enthalpy change, 7.64 kJ/mol) indicate that it is spontaneous and endothermic for As(V) to adsorb on CF@NiFe 2 O 4 . Potential mechanisms such as surface complexation, electrostatic interaction, and hydrogen bonding were suggested. This innovative approach offers a novel method for utilizing LDHs-based adsorption materials and recycling waste polymers.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2022
·Vol. 15
·期 13
·4645
·
IF 3.252
Dandan Guo,Jun Chi,Hongmei Yu,Guang Jiang,Zhigang Shao
The development of an efficient and durable oxygen evolution reaction (OER) electrode is needed to solve the bottleneck in the application of an anion exchange membrane water electrolyzer (AEMWE). In this work, the self-supporting NiFe layered double hydroxides (NiFe LDHs) “nanoflower” cluster OER electrode directly grown on the surface of nickel fiber felt (Ni fiber) was synthesized by a one-step impregnation at ambient pressure and temperature. The self-supporting NiFe LDHs/Ni fiber electrode showed excellent activity and stability in a three-electrode system and as the anode of AEMWE. In a three-electrode system, the NiFe LDHs/Ni fiber electrode showed excellent OER performance with an overpotential of 208 mV at a current density of 10 mA cm−2in 1 M KOH. The NiFe LDHs/Ni fiber electrode was used as the anode of the AEMWE, showing high cell performance with a current density of 0.5 A cm−2at 1.68 V and a stability test for 200 h in 1 M KOH at 70 °C. The electrocatalytic performance of NiFe LDHs/Ni fiber electrode is due to the special morphological structure of “nanoflower” cluster petals stretching outward to produce the “tip effect,” which is beneficial for the exposure of active sites at the edge and mass transfer under high current density. The experimental results show that the NiFe LDHs/Ni fiber electrode synthesized by the one-step impregnation method has the advantages of good activity and low cost, and it is promising for industrial application.Keywords:NiFe layered double hydroxides (NiFe LDHs);oxygen evolution reaction (OER);anion exchange membrane water electrolyzer (AEMWE)
研究领域:
电化学
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材料科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）