ChemPlusChem
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2013
·Vol. 78
·期 6
·481-485
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IF 0
Shichao Du,Zhiyu Ren,Yang Qu,Jian-qiang Wang,Lingjun Kong,Keying Shi,Buhe Bateer,Honggang Fu
Graphical Making a stand : By means of in situ reduction and self-assembly at an unconventional liquid–liquid interface, free-standing ultrathin cobalt nanosheets (CoNs) consisting of nanosized Co clusters were successfully synthesized (see figure). The as-prepared CoNs display ferromagnetic behavior and a large thermal irreversibility. This strategy has been used also in the synthesis of Fe and Ni nanosheets.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
Nanoscale
·
2023
·Vol. 15
·期 41
·16741-16751
·
IF 6.7
Jin Song,Fenglong Wu
The hydrolysis of ammonia borane (NH3BH3) on metal-based heterogeneous catalysts under light irradiation has been considered as an efficient technique for hydrogen (H2) generation, in which the activity of the catalyst can be improved by increasing the electron density of the active metal. However, studies focused on reducing the electron density of the active metal are rare. Here, we report an electron density manipulation strategy to prepare highly electron-deficient ultrathin Co nanosheets via transferring nanosheets to support mesoporous Cr2O3 by simple one-step in situ reduction (denoted as Co/Cr2O3). X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) spectra confirm the formation of electron-deficient Co nanosheets and the Co–O–Cr bond due to electron transfer from the nanosheets to mesoporous Cr2O3. Importantly, the Co–O–Cr bond can work as a bridge to accelerate the electron transfer under light irradiation and then improve the electron-deficiency degree of Co nanosheets. As a result, the optimal Co/Cr2O3 exhibits a high intrinsic catalytic performance with the turnover frequency (TOF) value of 106.8 min−1 and significantly reduces the activation energy (Ea) to 16.8 kJ mol−1 under visible light irradiation, which make it among the best ever recorded monometallic Co-based catalyst with enriched electrons. The density functional theory (DFT) calculation results suggest that the electron-deficient Co nanosheets are responsible for the greatly decreased H2O activation and dissociation energy barriers and then the acceleration of the evolution of H2. The work provides a new perspective for designing high efficiency catalysts for H2 production, which is beneficial for relative energy conversion and storage catalysis.
研究领域:
材料科学
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催化化学
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能源转换与存储
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2021
·Vol. 25
·期 4
·437-444
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IF 3.106
Cao Ding,Dong Yingying,Tang Ying,Ye Yaoyao,Hu Shui,Guo Zhenguo,Li Xinhua
A facile and efficient electrocatalyst for hydrogen evolution reaction (HER) to produce hydrogen is very important for future energy. In this paper, amorphous manganese–cobalt nanosheets are successfully prepared by electrospinning on a foamed nickel substrate. It is found that the manganese (Mn) introduction in manganese–cobalt composites can simultaneously enhance their electrocatalytic performances. As a result, benefitting from the 3D structure, the self-supported Mn–Co hydroxides exhibits unprecedented HER activity with a relatively low overpotential of 100 mV at 10 mA cm −2 and has a possibility for the large-scale production of hydrogen. Graphic Abstract Amorphous PVP/Mn 4 Co nanofibers formed by electrospinning on Ni foam (NF) has remarkable catalytic activity and stability for HER after operation for 6 h in 1 M KOH, with a low overpotential of 0.1 V at 100 mA cm −2 , a low Tafel slope of 65.4 mV dec −1 .
研究领域:
材料科学
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能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Liuting Zhang,Zeliang Cai,Xinqiao Zhu,Zhendong Yao,Ze Sun,Liang Ji,Nianhua Yan,Beibei Xiao,Lixin Chen
Magnesium, a cheap and abundant metal, holds tremendous promise for on-board hydrogen storage over the past several decades. However, the practical application of MgH 2 is still hampered by various challenges, including a high efficient catalyst. Zirconium and Zr-based alloys show great potential to serve as hydrogen transfer center due to their high activity in hydrogen dissociation and diffusion. In this paper, ZrCo nanosheets were successfully prepared via a facile wet-chemical technique and then introduced to improve the hydrogen storage properties of MgH 2 . With the addition of 10 wt% ZrCo nanosheets, the modified MgH 2 composite could desorb approximately 6.3 wt% H 2 within 5 min at 300 °C and absorb 4.4 wt% H 2 under 3 Mpa hydrogen pressure in 10 min even at 120 °C. The de/hydrogenation activation energy were calculated to be 90.4 ± 1.6 kJ/mol and 57.6 ± 1.0 kJ/mol for the MgH 2 +10 wt% ZrCo composite, which reasonably explain the remarkably improved de/hydrogenation performance. X-Ray Diffraction (XRD) and Transmission electron microscope (TEM) results revealed that hydrogen could be diffused between the composite more easily with the presence of well dispersed ZrCo, which acted as “hydrogen pump” for hydrogen boundaries/interface diffusion along the Mg/MgH 2 interfaces. Theoretical calculations revealed that the Mg–H bonds were extracted and weakened when adsorbed on the surface of ZrCo. Furthermore, the MgH 2 +10 wt% ZrCo composite showed superior cycling performance with the aid of graphene, indicative of potential application in the nearest future in the area of hydrogen storage.
研究领域:
材料科学
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能源存储
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2023
·
IF 7.2
Yuanpeng Qian,Mengliang Hu,Liping Li,Xuepeng Liu,Shuqi Cao,Chuigen Guo
Nickel-based materials exhibit great potential in the field of hydrogen evolution reaction (HER), however, the low catalytic active site and poor corrosion resistance still limit further application. Herein, a novel 3D self-supporting electrode of graphene oxide/nickel-cobalt/carbonized wood (GO/Ni–Co/CW) based on porous carbon is developed. The self-supporting structure of the electrode effectively prevents the shedding of catalytic materials, while the exposed active sites of the Ni–Co nanosheets ensure excellent catalysis and the decoration of GO further enhances the HER performance. Evidently, GO/Ni–Co/CW requires an overpotential of 52 mV in 0.5 M H 2 SO 4 and 70 mV in 1 M KOH to achieve a current density of 10 mA cm −2 . Furthermore, the introduction of GO greatly improves the stability performance of the electrode due to its corrosion resistance, as found by the catalytic stability performance test. As a new idea, GO decorated Ni–Co nanosheets grown on wood-based porous carbon as electrodes fully combine and exploit the advantages of CW's 3D porous structure , Ni–Co nanosheets' catalytic activity , and GO's corrosion resistance, which provide an effective strategy for novel nickel-based HER electrocatalysts .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-9
·
IF 15.7
Zhou Yin,Yin Kun,Huang Yingying,Li Jiapei,Zhu Anquan,Lin Dewu,Gan Guoqiang,Zhang Jianfang,Liu Kai,Zhang Tian,Liu Kunlun,Luan Chuhao,Yang Huawei,Chen Hou,Guo Shaojun,Zhang Wenjun,Hong Guo
Charge overpotential for oxygen evolution reaction is a crucial parameter for the energy conversion efficiency of lithium-oxygen (Li-O 2 ) batteries. So far, the realization of low charge overpotential via catalyst design is a grand challenge in this field, which usually exceeds 0.25 V. Herein, we report an orbital reconstruction strategy to significantly decrease the charge overpotential to the low 0.11 V by employing PdCo nanosheet catalyst under a low-loading mass (0.3 mg/cm 2 ) and capacity (0.3 mAh/cm 2 ). Experimental and theoretical calculations demonstrate that the precise d-d orbital coupling ( d xz - d xz , d yz - d yz and d z 2 - d z 2 ) between the low-electronegativity Co and Pd leads to the reconstruction of Pd 4 d orbitals in PdCo nanosheets, thereby resulting in a downward shift of all the three active Pd 4 d orbitals ( d z 2 , d xz and d yz ) relative to that of Pd nanosheets. Furthermore, the highest energy level of the Pd 4 d z 2 orbital in PdCo is lower than the lowest energy levels of the Pd 4 d xz and 4 d yz orbitals in pure Pd, significantly decreasing the charge activation energy and achieving a highest energy conversion efficiency of 91%. This finding provides the orbital-level tuning into rational design of highly efficient electrocatalysts for Li-O 2 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
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xiaoyu Zhang,Ge Ma,Lingling Shui,Guofu Zhou,Xin Wang
Ultrathin Co3O4 nanosheets (NSs) with abundant oxygen vacancies on conductive carbon nanotube (CNT) nanocomposites (termed as Co3O4-NSs/CNTs) are easily achieved by an effective NaBH4-assisted cyanogel hydrolysis strategy under ambient conditions. The specific capacitance of Co3O4-NSs/CNTs with 5% CNT mass can reach 1280.4 F g–1 at 1 A g–1 and retain 112.5% even after 10 000 cycles, demonstrating very high electrochemical capability and stability. When assembled in the two-electrode Co3O4-NSs/CNTs-5%//reduced graphene oxide (rGO) system, a maximum specific energy density of 37.2 Wh kg–1 (160.2 W kg–1) is obtained at room temperature. Ultrathin structure of nanosheets, abundant oxygen vacancies, and the synergistic effect between Co3O4-NSs and CNTs are crucial factors for excellent electrochemical performance. Specifically, these characteristics favor rapid electron transfer, complete exposure of the active interface, and sufficient adsorption/desorption of electrolyte ions within the active material. This work gives insights into the efficient construction of two-dimensional hybrid electrodes with high performance for the new-generation energy storage system.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 23
·18922-18937
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IF 2.779
Lu Jinghua,Wang Jiaheng,Gong Jiaxu,Hu Cunhai
The design of structure and morphology is the key to improve the performance of supercapacitors. This work reports a facile method for the synthesis of MXene-NiCo 2 O 4 @NiCo-MOF/CC(M-NiCo 2 O 4 @NiCo-MOF/CC) materials by hydrothermal method and electrodeposition. Density functional theory (DFT) calculations illustrating the change in density of states (DOS) at the heterojunction demonstrate that the composite can improve electronic performance. M-NiCo 2 O 4 @NiCo-MOF/CC electrode can reach a high specific capacity of 1150.0 C g −1 (2091.0 F g −1 ) at 1 A g −1 , with a retention of 90.3% after 6000 cycles, reflecting excellent electrochemical performance. In addition, the assembled M-NiCo 2 O 4 @NiCo-MOF/CC//AC device exhibits excellent performance, and can reach a high energy density of 56.7 Wh kg −1 at 750 W kg g −1 , reflecting the broad application prospects.
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
ADVANCED FUNCTIONAL MATERIALS
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2025
·
IF 19
Wen Zhang,Yingxiu Zhao,Jiayi Li,Yu Miao,Pengkai He,Zexing Wu,Yang Zhang,Guang-Rui Xu,Lei Wang
The capacity of C‒C bond cleavage determines the pathway selectivity during the ethanol oxidation process. Herein, ultra-thin monodisperse PdCo nanosheets with an average diameter of 33 nm are successfully synthesized and the interface of Pd-O-Co is further constructed due to the introduction of lattice oxygen. Due to their ultra-thin nanosheet structure, unique surface electronic structures driven by lattice oxygen, and alloying effect, the prepared PdCo/Pd-O-Co nanosheets (PdCo/Pd-O-Co NSs) show excellent ethanol oxidation reaction (EOR) activity and stability. The mass activity and specific activity of PdCo/Pd-O-Co NSs are 12.43 A mg −1 and 22.01 mA cm −2 for EOR, which exceeded PdCo nanosheets, Pd nanosheets and commercial Pd black. In situ FTIR spectroscopy and theoretical calculation identified that lattice oxygen introduced after square-wave potential treatment can promote the cleavage of the C‒C bond. Through the introduction of lattice oxygen combined with lattice strain engineering, the PdCo/Pd-O-Co NSs surface is optimized to promote the generation of strong p-d orbital hybridization, which led to the upward shift of the d-band center and the electron delocalization effect, effectively promoting the C‒C bond cleavage and improving the anti-poisoning ability.
研究领域:
材料科学
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催化化学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Wang Tuhui,Zhang Lening,Xin Hua
Portable devices possess powerful application prospects in on-site sensing without the limitation of bulky instruments. Given the relevance of pesticides to food safety, we herein fabricated a robust gold nanocluster (AuNC)-based hydrogel test kit for precisely quantified chlorpyrifos by using a three-dimensional (3D) printed subsidiary device. In this work, the fluorescence of AuNC-based hydrogel could be efficiently quenched by cobalt oxyhydroxide nanoflakes (CoOOH NFs) through the Förster resonance energy transfer effect. Chlorpyrifos as an acetylcholinesterase inhibitor controls the enzymatic hydrolysis reaction and further regulates the production of thiocholine that could decompose CoOOH nanoflakes into Co2+, resulting in the fluorescence response of AuNC-based hydrogel. By using a homemade subsidiary device and smartphone, the fluorescence color was transformed into digital information, achieving the on-site quantitative detection of chlorpyrifos with the limit of detection of 0.59 ng ml−1. Owing to specific AuNC signatures and hydrogel encapsulation, the proposed fluorescence hydrogel test kit displayed high sensitivity, good selectivity, and anti-interference capability in a real sample analysis, providing great potential in on-site applications.
研究领域:
食品安全
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分析化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Fangzheng Liu,Yunfei Ouyang,Xinyao Xie,Junwei Ke,Lu Qiu,Zhaoyang Zhang,Shiyi Huang,Xiangxiang Chen
To effectively detect the volatile terpineol and butyl xanthate gases produced during the flotation process in mineral processing plants, Co 3 O 4 nanosheets, Co 3 O 4 nanoparticles, and Co 3 O 4 nanoflowers were synthesized via one-pot hydrothermal method as sensing materials. The crystal structure and microscopic morphology of the synthesized materials were characterized using XRD, SEM and TEM, respectively. The specific surface area and pore-size distribution were recorded using BET. The elemental distribution and valence states were analyzed using XPS, and the chemical bonds and functional groups were analyzed using FTIR. The gas sensing properties demonstrated that Co 3 O 4 nanosheets exhibited superior sensing performance over Co 3 O 4 nanoparticles and Co 3 O 4 nanoflowers. The Co 3 O 4 nanosheets showed maximum responses of 8.06 and 9.17 to 50 ppm volatile terpineol and 200 ppm volatile butyl xanthate gases at the optimal operating temperature of 200 °C, respectively, as well as favorable gas sensing response-recovery characteristics and reproducibility. The superior performance is attributed to the abundant oxygen vacancies and the distinctive porous structure of Co 3 O 4 nanosheets. This work significantly contributes to the development of high-performance gas sensors for the mining industry.
研究领域:
材料科学
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传感器技术
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矿物加工工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
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IF 5.3
Haixia Zhang,Wenyuan Dai,Ru Liu,Junying Xiang,Yanhui Song,Ying Hou,Hong Wei,Peizhi Liu,Bingshe Xu,Jianguo Liang,Junjie Guo
ZIF-67-derived Co–N–C catalysts exhibit efficient water-splitting performance and thus have attracted intense research interest. However, the serious Co agglomeration and loss of most N atoms due to high-temperature pyrolysis limit the further improvement of their electrocatalytic performance. Herein, we report a ZIF-67-derived 2D porous N-doped carbon nanosheet decorated with a Co nanoflake catalyst (Co@NC/CC-500) for OER and HER by a facile pyrolysis method at a low temperature of 500 °C. Benefiting from the ultrahigh N doping (12 atom %) and uniformly dispersed Co nanoflakes on 2D porous carbon nanosheets, which lead to a high content of Co–N active sites, the Co@NC/CC-500 catalyst exhibits outstanding performance toward the HER and OER with overpotentials of 95 and 183 mV at 10 mA cm–2 in 1 M KOH, respectively. Furthermore, the alkaline water electrolyzer using Co@NC/CC-500 as the cathode and anode catalysts can achieve a current density of 10 mA cm–2 at a cell voltage of 1.52 V. This special low-temperature production method may be extensively utilized to create precisely defined monometal or bimetal nanoflakes decorated on 2D porous N-doped carbon nanosheets for diverse electrochemical energy applications.
研究领域:
材料科学
·
电化学能源
✓ 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）