JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Jianghong You,Yiming Yuan,Chen Zhang,Haoming Xu,Mingyao Chen,Ying Wang,Dongsheng Chen
The transition metal oxide of nickel cobaltite (NiCo 2 O 4 ) has gained more and more attention from battery industry for its excellent properties of high capacitance and cycling stability. However, its performance when used in supercapacitors is compromised due to its limited active sites and poor conductivity. Herein, a 3D (three-dimensional) hierarchical and high-performance material of NiCo 2 O 4 @MXene@LDH (LDH: layered double hydroxide) composite was designed and synthesized. In the material, NiCo 2 O 4 nanorods form a skeleton of nanosheet arrays on layered MXene; and on the nanosheet arrays, NiCo-LDH nanoparticles are attached to form a 3D hierarchical structure, extending the electrochemically active sites, suppressing the agglomeration of NiCo-LDH and producing hierarchical channels that promote electron and ion transport. Density functional theory (DFT) calculations and the results of Ultraviolet–visible (UV–Vis) spectrophotometry indicated that the introduction of MXene and NiCo-LDH induces a redistribution of the electronic states of NiCo 2 O 4 due to the formation of a heterointerface, thereby decreasing its bandgap by about 1.42 eV. The X-ray photoelectron spectroscopy (XPS) analysis further demonstrated the negative shift in the initial binding energies of nickel (Ni) and cobalt (Co) atoms, which is due to their transition of spin states; and this is in agreement with the high intensity of electron paramagnetic resonance (EPR) peak in the NiCo 2 O 4 @MXene@LDH composite. The in situ Raman analysis reveals that the enhanced energy storage performance originates from the accelerated formation and increased exposure of NiCoOOH active species during electrochemical cycling. The synergistic effect of MXene and NiCo-LDH introduced into NiCo 2 O 4 enhanced the supercapacitor in terms of power and energy densities. It was indicated that the supercapacitor fabricated from NiCo 2 O 4 @MXene@LDH supercapacitor exhibited a specific capacitance of 5066 F g −1 at 1 A g −1 , and a capacitance retention of 97.82 % after 10,000 charge cycles at 10 A g −1 . Moreover, an asymmetric supercapacitor (ASC) device with a NiCo 2 O 4 @MXene@LDH//AC configuration was developed. The supercapacitor presented an energy density and power density of 70.11 Wh kg −1 and 850.22 W kg −1 , respectively. The redistribution of electronic states and decreased bandgap could facilitate the creation of NiCo 2 O 4 -based materials with customized features for supercapacitors.
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PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2018
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IF 3.235
Xu Wang,Peng Zhang,Tong Wang,Osamu Yamamoto,Nobuyuki Imanishi,Miao Wang
Mesoporous NiCo 2 O 4 nanoneedle arrays on graphene film grown directly on a three-dimensional Ni foam have been fabricated by a facile hydrothermal method , accompanied by annealing under air atmosphere. The BET specific surface area of NiCo 2 O 4 @graphene film@Ni foam is as high as 47.65 m 2 g −1 . The porous composites served as a binder-free anode material for lithium-ion batteries display an excellent and stable electrochemical performance with high specific capacities of 1232 mAh g −1 at the current density of 500 mA g −1 over 100 cycles and 1493 mAh g −1 at the current density of 1500 mA g −1 after 230 cycles with Coulombic efficiency higher than 97%. Moreover, a fairly high rate capacity of 586 mAh g −1 retained even at a high current density of 8000 mA g −1 . The outstanding electrochemical performance should be attributed to synergetic effect of NiCo 2 O 4 nanoneedle arrays with mesoporous nature and high specific area as well as graphene substrate supporting, which can accommodate the volume variation during the electrochemical reactions and facilitate the ion and electron transmission.
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DOI
高影响因子
Journal of Physical Chemistry C
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2018
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IF 4.484
Xiaona Wang,Juan Sun,Jingxin Zhao,Zhenyu Zhou,Qichong Zhang,Ching-ping Wong,Yagang Yao
Fiber-shaped supercapacitors (FSC), among the most promising next-generation flexible energy storage devices, attract tremendous attention due to their high power density and rapid charging and discharging. However, their practical application is hindered by the low energy density that results from inferior specific capacitance and a limited voltage window. Herein, we design a flexible fiber-shaped asymmetric supercapacitor (FASC) with high energy density using vanadium nitride (VN) nanowires (NWs) on carbon nanotube fiber (CNTF) as negative electrode and ultrathin Ni(OH)2 nanosheet wrapped nickel cobalt oxide (NiCo2O4) to form a hierarchical nanowire array (HNWA) structure on CNTF as positive electrode. As-assembled FASC device has a maximum operational voltage of 1.6 V, with a highest areal capacitance of 291.9 mF/cm2 (106.1 F/cm3) and an energy density of 103.8 μWh/cm2 (37.7 mW/cm3). The FASC device possesses excellent reliability and achieves a retaining capacitance of more than 90% after 3000 bending cycles, which boosts practical applications for next-generation flexible energy storage devices.
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高影响因子
TALANTA
·
2024
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IF 5.6
Huanhuan He,Jia Zheng,Jian Su,Lian Xia,Yue Tang,Yuangen Wu
A novel aptamer LFA (Apt-LFA) strip is first constructed for ethyl carbamate (EC) detection, in which cationic polyethyleneimine (PEI) and anionic polyacrylamide (APAM) are used as double-capture agents. The black NiCo 2 O 4 nanoparticles (NCO NPs) encapsulated by EC1-34 aptamer are employed as recognition probes. The added EC will bind to EC1-34 aptamer on the probes, so that the test-line (T-line) immobilized with APAM can electrostatically capture the exposed NCO NPs. The control-line (C-line) sprayed with PEI can capture the excessive black recognition probes. The peroxidase-like activity of bimetallic NCO NPs is employed as signal amplification to improve the sensitivity of Apt-LFA strip. The naked eye discernible concentration of EC is 5 μg L −1 and the detection limit (LOD) is as low as 1.36 μg L −1 . The Apt-LFA strip has the advantages of strong stability, simplicity and low cost, which provide a new method for EC detection and offer a new way for designing LFA.
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高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2021
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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.
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高影响因子
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