Hierarchical Core-shell Nanostructures Research Articles

Phosphorylated Co(OH)2@NiFe-LDH core–shell heterostructure for highly efficient alkaline water splitting

The development of transition metal bifunctional electrocatalysts with high activity, stability and cost-effectiveness is necessary for the overall water decomposition. In this work, a phosphorylated core–shell heterostructure bifunctional catalytic material with a nickel foam carrier, a Co(OH)2 nanowire array core and an ultrathin NiFe layered double hydroxide (NiFe-LDH) shell is synthesized. The solid contact between the NiFe-LDH shell and the highly conductive Co(OH)2 core brings about excellent electrical connectivity and an integrated hierarchical nanostructure that greatly improves the active specific surface area. Meanwhile, the phosphorylated hierarchical core–shell nanostructure enables the presence of a large amount of amorphous material at the edges, which leads to excellent activity and stability for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER).

A novel P, N doped organic-inorganic hierarchical core-shell nanostructures: Reducing the fire risk of epoxy resin

The wide application of epoxy resin (EP) causes a great potential fire risk to humans and the environment. To effectively reduce the fire risk of EP, we designed a novel P, N-doped organic-inorganic hierarchical core-shell nanostructure (BN@PEI@UiO-66@PPA). Encouragingly, with only 2 wt% of BN@PEI@UiO-66@PPA, the peak heat release rate (PHRR) and total heat release (THR) were reduced by 47.2 % and 47.9 %, respectively, compared with those of pure EP, indicating a considerable enhancement in flame retardancy. The peak smoke release rate (PSPR), total smoke production (TSP), peak CO production rate (PCOPR), and peak CO2 production rate (PCO2PR) were significantly reduced by 46.0 %, 52.7 %, 72.1 %, and 75.1 %, respectively, compared with those of pure EP, indicating a significant reduction in fire toxicity. In addition, the mass of the char residue of BN@PEI@UiO-66@PPA/EP increased by 185.3 %, and the graphitization degree and thermal stability of the char were significantly improved. The results indicate that the various components in BN@PEI@UiO-66@PPA were functionally different and cross-assisted to form dense P-N-C char with high graphitization and high thermal stability, which effectively improved the fire safety of EP. This work provides a new reference for the construction of multi-component hierarchical structures to optimize their application in the field of fire safety of polymer composites.

Defective core–shell NiCo2S4/MnO2 nanocomposites for high performance solid-state hybrid supercapacitors

The roles of oxygen vacancies to enhance the electrochemical performance were not clearly explained in comprehensive research. Herein, the vertically oriented NiCo2S4/MnO2 core–shell nanocomposites are in situ grown on the nickel foam (NF) surface and activated by oxygen vacancy engineering via a chemical reduction method. The scanning electron microscope (SEM) and transmission electron microscope (TEM) results show the shell-MnO2 is well coated on the core-NiCo2S4. The hierarchical core–shell nanostructures synergistically increase conductivity and provide rich faradaic redox chemical reactions. Moreover, the density functional theory (DFT) calculations further indicate that the electronic properties and structure properties in NiCo2S4/MnO2 electrode of reduction for 60 min (NiCo2S4/MnO2-60) are effectively adjusted by introducing oxygen vacancies. Impressively, the NiCo2S4/MnO2-60 electrode delivers substantially appreciable areal capacity of 2.13 mAh·cm−2 couple with superior rate capability. The as-prepared high-performance electrode material can assemble into solid-state hybrid supercapacitor. The fabricated NiCo2S4/MnO2-60//AC device exhibits an exceptional energy density of 43.16 Wh·kg−1 at a power density of 384.21 W·kg−1 and satisfactory cyclic stability of 92.1 % at current density of 10 mA·cm−2 after 10,000 cycles. In general, the work demonstrates the significance of NiCo2S4/MnO2-60 as a highly redox active electrode material for future practical application in supercapacitors.

In situ preparation of hierarchical CuO@NiCo LDH core–shell nanosheet arrays on Cu foam for highly sensitive electrochemical glucose sensing

3D hierarchical core–shell nanostructures of CuO nanorods with NiCo LDH nanosheet arrays (CuO@NiCo LDH NSAs/CF) acting as electrodes have excellent sensing performance for glucose with a low detection limit of 0.16 μM at S/N = 3.

CuxO nanorod arrays shelled with CoNi layered double hydroxide nanosheets for enhanced oxygen evolution reaction under alkaline conditions

Exploration of highly efficient and cost-effective oxygen evolution reaction (OER) electrocatalysts is of crucial importance for the development of water splitting. In recent years, Cu-based materials have been widely concerned in OER due to their non-toxicity, rich reserves and highest reversibility. Meanwhile, CuxO nanorods is easy to be prepared in industry. Herein, we report a fast preparation method to construct an integrated CuxO@CoNi-LDH electrocatalyst with a unique 1D nanowire-2D nanosheet hierarchical core–shell structure by electrodepositing CoNi-LDH nanosheet arrays directly onto CuxO nanorods (CuxO were in situ-created on the Cu foam) at a large deposition voltage of −3.0 V vs SCE. The unique heterogeneous core–shell nanostructure, large deposition amount of CoNi-LDH and the synergistic effects between CuxO core and CoNi-LDH shell can provide abundant active sites, rich open-channels and reduced charge transfer resistance (Rct) for effective oxygen release and facile electron transport. Consequently, the optimized CuxO@CoNi-LDH/CF exhibits a low overpotential of 207 mV in 1 M KOH solution at the current density of 10 mV cm−2 and a small Tafel slope of 50.1 mV dec−1. After 60 h of long-term stability test, the catalytic performance is only slightly weakened. This work demonstrates a new approach to design the high-performance LDH and Cu-related OER catalysts by constructing a unique hierarchical core–shell nanostructure.

Fabrication of oxygen-vacancy abundant MnO2 nanowires@ NiMnxOy-δ nanosheets core-shell heterostructure for capacity supercapacitors

Structure instability and poor electrical conductivity are two major obstacles to realizing high performance of MnO2-based pseudocapacitor material. The construction of unique hierarchical core-shell nanostructures, therefore, plays an important role in the efficient enhancement of the rate capacity and the stability of this material. Herein, a stable MnO2@NiMnxOy-δ core-shell heterostructure is prepared via a simple liquid-phase reaction combined with heat-treatment method, composed of ultrathin NiMnxOy-δ nanosheets with oxygen vacancies uniformly growing on the surface of ultralong MnO2 nanowires. Electrochemical test results show that the electrode exhibits a specific capacitance of 463.5 C g−1 at 1 A g−1 and has an excellent capacitance retention as high as 94.9% after 20,000 cycles. Compared with the MnO2@NiMnxOy nanowires, the introduction of oxygen vacancies in the ultrathin nanosheets of the MnO2@NiMnxOy-δ core-shell heterostructure can provide a large number of surface active sites to accelerate electron/ions transport during electrochemical reaction. Moreover, the interfacial behavior of the electrode reaction can be also adjusted due to the potential synergistic effect between one-dimensional nanowires and two-dimensional nanosheets, further the MnO2@NiMnxOy-δ core-shell heterostructure demonstrating the superior cyclic stability.

Supramolecular Core-Shell Nanoassemblies with Tumor Microenvironment-Triggered Size and Structure Switch for Improved Photothermal Therapy.

Photothermal therapy (PTT) is demonstrated to be an effective methodology for cancer treatment. However, the relatively low photothermal conversion efficiency, limited tumor accumulation, and penetration still remain to be challenging issues that hinder the clinical application of PTT. Herein, the core-shell hierarchical nanostructures induced by host-guest interaction between water-soluble pillar[5]arene (WP5) and polyethylene glycol-modified aniline tetramer (TAPEG) are constructed. The pH-responsive performance endows the core-shell nanostructures with size switchable property, with an average diameter of 200nm in the neutral pH and 60nm in the acidic microenvironment, which facilitates not only tumor accumulation but also tumor penetration. Moreover, the structure switch of WP5⊃TAPEG under acidic microenvironment and the dual mechanism regulated extending of п conjugate, inclusion in the hydrophobic cavity of WP5 and the dense distribution in the core-shell structured assemblies, dramatically enhance the absorption in the near-infrared-II region and, further, the photothermal conversion efficiency (60.2%). The as-designed intelligent nanoplatform is demonstrated for improved antitumor efficacy via PTT.

Facile construction of hierarchical Co3S4/CeO2 heterogeneous nanorod array on cobalt foam for electrocatalytic overall water splitting

Herein, a hierarchical Co3S4/CeO2 nanorod array on cobalt foam (Co3S4/CeO2-CF) was successfully constructed via a facile one-step hydrothermal method. The fabrication of Co3S4/CeO2-CF was confirmed by X-ray diffraction, scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM). It is observed that CeO2 nanorod was fully covered with Co3S4 nanosheets, forming a hierarchical core–shell nanostructure. Furthermore, CeO2 and Co3S4 were doped with each other during the one-step hydrothermal process, forming a heterogeneous Co3S4/CeO2 nanostructure. Density functional theory (DFT) calculations suggest that the introduction of CeO2 in Co3S4 is effective in reducing the free energy barrier of OER process. To achieve current density of 10 mA cm−2, only small overpotentials of 74.9 mV and 213 mV are required for HER and OER in 1.0 M KOH solution, respectively. In particular, the Co3S4/CeO2-CF based electrolysis cell for overall water splitting only needs an output voltage of 1.64 V in the alkaline medium, lower than that of Pt/C–RuO2-based electrolysis cells (1.70 V). Such hierarchical heterogeneous catalyst also shows ultra-stable catalytic activity. Therefore, with the favorable heterointerfaces and hierarchical structures, Co3S4/CeO2-CF could be a promising bifunctional electrocatalyst for overall water splitting and this study may also provide a facile method for the preparation of hierarchical heterogeneous nanostructured materials.

Gram-scale synthesis of ZnS/NiO core-shell hierarchical nanostructures and their enhanced H2 production in crude glycerol and sulphide wastewater

Design and development of the efficient and durable photocatalyst that generates H2 fuel utilizing industrial wastewater under solar light irradiation is a sustainable process. Innumerable photocatalysts have been reported for efficient H2 production, but their large-scale production with the same efficiency of H2 production is a challenging task. In this study, a few gram-scale syntheses of ZnS wrapped with NiO hierarchical core-shell nanostructure via the surfactant-mediated process has been reported. Morphology and crystal structure analysis of ZnS/NiO showed spherical shaped hierarchical core-shell with cubic and face-centered cubic crystal structures. The surface examination confirmed the presence of Zn2+, S2−, Ni2+ and O2− ions in the nanocomposite. The photocurrent and photoluminescence studies of pristine and nanocomposites revealed that core-shell material is non-corrosive with a prolonged life-time of photo-excitons. Parametric studies on photocatalytic H2 generation in lab-scale photoreactor using crude glycerol in water recorded a high rate of H2 generation of 9.3 mmol h−1.g−1 of catalyst under the simulated solar light irradiation. Optimized reaction parameters are extended to a demonstrative photoreactor containing aqueous crude glycerol produced 18.5 mmol h−1 of H2 generation under the natural solar light irradiation. The same nanostructures were further tested with the simulated sulfide wastewater and the optimized catalyst showed H2 production of 350 mL h−1. The experimental results of time-on stream and catalytic stability demonstrated that ZnS/NiO hierarchical core-shell nanostructures can be recyclable and reusable for the continuous photocatalytic H2 generation.

Construction of hierarchical sea urchin-like manganese substituted nickel cobaltite@tricobalt tetraoxide core-shell microspheres on nickel foam as binder-free electrodes for high performance supercapacitors

Construction of binder-free electrodes with hierarchical core-shell nanostructures is considered to be an effective route to promote the electrochemical performance of supercapacitors. In this work, the porous Ni0.5Mn0.5Co2O4 nanoflowers anchored on nickel foam are utilized as framework for further growing Co3O4 nanowires, resulting in the hierarchical sea urchin-like Ni0.5Mn0.5Co2O4@Co3O4 core-shell microspheres on nickel foam. Owing to the advantages brought by unique porous architecture and synergistic effect of the multi-component composites, the as-prepared electrode exhibits a high specific capacitance (931 F/g at 1 A/g), excellent rate performance (77% capacitance retention at 20 A/g) and outstanding cycle stability (92% retention over 5000 cycles at 5 A/g). Additionally, the assembled Ni0.5Mn0.5Co2O4@Co3O4//AC (activated carbon) asymmetric supercapacitor achieves a high energy density (50 Wh/kg at 750 W/kg) and long durability (88% retention after 5000 cycles).

High-performance adjustable manganese oxides hybrid nanostructure for supercapacitors

Manganese oxides based supercapacitors have shown great potential in portable electronics. However, the limited energy density of MnO2-based electrodes is still a developmental bottleneck that restricts their practical applications. In this work, we use hydrothermal method to grow highly regular MnO2 nanoclusters on oxidized carbon fiber as sponge layer, in which Mn3O4 nanospheres are expanded in MnO2 by hydrothermal method again, forming a hierarchical core-shell nanostructure. The activatable nanoparticles undergo a phase change by cycling protocol, providing high accessible surface area and more exposed active sites. The resulting MnO2/Mn3O4 electrode exhibits an excellent performance such as a superior specific capacitance of 1709 F g − 1 at 1 A g − 1 in 1.0 M Na2SO4 aqueous electrolyte, a good electrochemical cycling stability with 91.9% and 71.67% retentions of initial specific capacitance and nearly 100% coulumbic efficiency respectively after 6000 and 20,000 cycles at 10 A g − 1. The assembled asymmetrical ASC displayed a maximum operating voltage of 1.9 V, a high specific capacitance of 198.6 F g − 1 at 0.8 A g − 1 and an exceptional energy density of 234 W h kg−1. These results open up new paths for exploring high-performance manganese oxide-based electrode materials and applying for advanced energy storage devices.

Construction of dual metal ferrite-based core-shell nanostructures as low-cost multimetal electrode for boosting energy density of flexible asymmetric supercapattery

We report the synthesis and fabrication of economically cheaper and binder-free hierarchical core-shell nanostructures of copper ferrite nanorods and nickel ferrite nanosheets (CuFe2O4–NR@NiFe2O4–NS) via a two-step wet chemical technique. The unique core-shell (nanorods@nanosheets) nanostructures offer multiple redox couples (Cu2+, Fe3+, and Ni2+), smaller ion diffusion path, and faster electron movement. When evaluated as an individual electrode in aqueous potassium hydroxide solution, the as-synthesized CuFe2O4–NR@NiFe2O4–NS electrode demonstrate superior electrochemical behaviour with concurrent specific capacity of 1366 C g−1 at current rate 1 A g−1, and 94% capacity retention over 10,000 cycles. A flexible asymmetric supercapattery device is assembled comprising positive electrode of CuFe2O4–NR@NiFe2O4–NS and negative electrode of reduced graphene oxide (rGO) with PVA-KOH semisolid electrolyte. The ASC cell manifest enhanced specific energy of 72 Wh kg−1, specific power of 0.287 kW kg−1 and outstanding cycle life (~97% of retention over 10,000 cycles at 10 A g−1). The superior specific capacity, capacity retention, and excellent cyclic life endow such multimetal ferrite-based core-shell architecture with tremendous potential for use as electrode materials for fabricating next generation energy storage devices.

Controllable preparation of core-shell Co3O4@CoNiS nanowires for ultra-long life asymmetric supercapacitors

Tricobalt tetroxide (Co3O4) with high theoretical capacity has been considered as a promising material for supercapacitors. However, the poor electrical conductivity and poor capacity retention hinder its further larger-scale application. Besides, a series of metal sulfides shows good thermal stability, mechanical stability and electrical conductivity. Here, hierarchical core-shell nanostructure is successfully synthesized by coating the Co3O4 nanowires with highly conductive CoNiS (Co3O4@CoNiS) by a facile two-step method of hydrothermal treatment and succeeding electrodeposition. And the core-shell structure presents high electrical conductivity, discharge capacity and good cycle life. The as-prepared Co3O4@CoNiS exhibited a high specific capacity of 1153.75 C g−1, which is 1.97 times as much as that of Co3O4. Furthermore, an asymmetric supercapacitor (ASC) was assembled by using the N/O co-doped porous carbon (NOPC) as negative electrode and the as-prepared Co3O4@CoNiS as positive electrode, which showed a high energy density of 46.95 Wh kg−1 at the power density of 400 W kg−1 and an ultra-stable capacity retention with 95.6% for 20,000 cycles. The cyclic stability of similar work is lower than that of our work, which provides a reference for the preparation of electrode materials with long-term cyclic stability.

Core-shell nanostructured MnO2@Co9S8 arrays for high-performance supercapacitors

Manganese dioxide (MnO2) with large theoretical capacity, low cost and rich reserves has been considered as one of the most promising advanced electrode materials of supercapacitors, but the shortage of electrochemical active sites and the inherent defects of electrical conductivity hinder its widespread application in high-performance supercapacitors. Herein, the hierarchical core-shell nanostructure has been rationally designed by coating highly electrically conductive Co9S8 on MnO2 arrays on Ni foam (MnO2@Co9S8/NF) using a simple solution-based method. The prepared MnO2@Co9S8/NF exhibits a high specific capacitance of 643.3 C g−1 at 3 mA cm−2, which is 3.4 and 10.1 times higher than the Co3O4@MnO2 and pristine MnO2 electrodes, respectively. Moreover, the asymmetric supercapacitor (ASC) with MnO2@Co9S8 composite electrode provides a high areal capacitance of 1540 mC cm−2 and a maximum energy density of 346.5 μW h cm−2 (35 Wh kg−1) at the power density of 2376 μW cm−2 (240 W kg−1). Importantly, the excellent cycling life with a capacitance retention of 97.5% after 36,000 cycles indicates the good stability of the core-shell structure of the composite electrode. These superior electrochemical properties of current materials are comparable to the most advanced MnO2-based electrodes for supercapacitors.

3D hierarchical carbon nanofibers/TiO2@MoS2 core-shell heterostructures by electrospinning, hydrothermal and in-situ growth for flexible electrode materials

Design and synthesis of unique core-shell heterostructures for flexible electrode materials have recently attracted intensive attention. In this work, 3D flexible carbon nanofibers (CNFs)/TiO2@MoS2 core-shell hierarchical nanostructures were prepared on the surface of CNFs by combining electrospinning, hydrothermal method and in situ growth. We investigated the behavior of CNFs/TiO2@MoS2 as electrode material, which showed desirable electrochemical performance in terms of ultrahigh specific capacitance and long-term stability. The CNFs/TiO2@MoS2 exhibited ultrahigh specific capacitance (510.4 F g−1 at 0.5 A g−1) superior to CNFs/TiO2 (53.8 F g−1 at 0.5 A g−1) and prominent rate capability at high scan rates. Specifically, the capacitance retention of CNFs/TiO2@MoS2 remained about 95.7% even after 3000 cycles at 3.5 A g−1, which indicates considerable cycling stability. Hence, this work presents a novel strategy for the construction of cost-effective, flexible and high-performance 3D electrode materials, and confers in-depth understanding of nanocomposites with relatively light quality. The fabricated nanocomposite can have attractive application prospects in energy storage systems and can even be extended to wearable and portable energy storage equipment.

Hierarchical core-shell electrode with NiWO4 nanoparticles wrapped MnCo2O4 nanowire arrays on Ni foam for high-performance asymmetric supercapacitors

Rational construction of MnCo2O4-based core-shell nanomaterials with distinctive and desirable architectures possesses great potential in the advanced electrode material of high-performance supercapacitors. Here, a new class of hierarchical core-shell nanowire arrays (NWAs) with a shell of NiWO4 nanoparticles and a core of MnCo2O4 nanowires is reported, which can significantly improve the electrochemical energy storage properties of supercapacitors. The unique core-shell structure endows the MnCo2O4@NiWO4 NWAs electrode with a high areal specific capacitance of 5.09 F cm−2 at a current density of 1 mA cm−2 and a superior cyclic retention of 96% after 5000 charge-discharge cycles, which are more preferable than those of MnCo2O4 NWAs electrode. More importantly, an aqueous electrochemical energy storage device (core-shell MnCo2O4@NiWO4 NWAs as the positive electrode and active carbon as the negative electrode, MnCo2O4@NiWO4//AC ASC) was assembled and shows a high energy density of 0.23 mWh cm−2 at a power density of 2.66 mW cm−2, and 0.09 mWh cm−2 at 16.00 mW cm−2, indicating hopeful potential for practical applications. This work highlights the significance of NiWO4 as a shell for hierarchical core-shell nanostructures, which can further improve the electron transport characteristic of the electrode material, thereby achieving performance breakthroughs in energy storage devices.

Hierarchical In2O3@SnO2 Core-Shell Nanofiber for High Efficiency Formaldehyde Detection.

In this work, three-dimensional (3D) hierarchical In2O3@SnO2 core-shell nanofiber (In2O3@SnO2) was designed and successfully prepared via a facile electrospinning and further hydrothermal methods. Vertically aligned SnO2 nanosheets uniformly grown on the outside surface of In2O3 nanofibers were clearly observed by field emission scanning electron microscopy. Besides, hierarchical core-shell nanostructure of In2O3@SnO2 was characterized by elemental maps using scanning transmission electron microscopy. The formaldehyde (HCHO) sensing performances of pure In2O3 nanofibers, SnO2 nanosheets, and In2O3@SnO2 core-shell nanocomposite were compared, and the In2O3@SnO2 nanocomposite possessed highest response value, fast response/recovery speed, best selectivity, and lowest HCHO detection limit. Specifically, the response value (Ra/Rg) of the In2O3@SnO2 nanocomposite reached 180.1 toward 100 ppm of HCHO gas, which was near 9 and 6 times higher than that of the pure In2O3 nanofibers (Ra/Rg = 19.7) and pure SnO2 nanosheets (Ra/Rg = 33.2), respectively. In addition, the gas sensor showed instantaneous response/recovery time (3/3.6 s) toward 100 ppm of HCHO at the optimal operation temperature of 120 °C. More importantly, the detection limit toward HCHO gas was as low as 10 ppb (Ra/Rg = 1.9), which could be used for trace HCHO gas detection. The excellent sensing properties of the In2O3@SnO2 were attributed to the synergistic effect of large specific surface areas of SnO2 nanosheet arrays, abundant adsorbed oxygen species on the surface, unique electron transformation between core-shell heterogeneous materials, and long electronic transmission channel of SnO2 transition layer. This work provides an efficient route for the preparation of novel hierarchical sensitive materials.

Efficient charge transfer and separation of TiO2@NiCo-LDH core-shell nanowire arrays for enhanced photoelectrochemical water-splitting

Efficient charge transfer and separation play a significant role in determining the photoelectrochemical (PEC) water-splitting performance of photocatalysts. Here, hierarchical nanowire arrays (NWAs) containing the TiO2 nanowire core and nickel-cobalt layered double hydroxide (NiCo-LDH) shell were synthesized by combining a hydrothermal method with a facile electrochemical-deposition process. The hierarchical structure not only forms heterojunctions between the TiO2 core and NiCo-LDH shell but also provides active sites for water-splitting reaction, achieving the charge transfer efficiency up to 87% and the charge separation efficiency up to 42% at 1.23 V vs. reversible hydrogen electrode (RHE) under one sun illumination. The excellent PEC water-splitting performance of TiO2@NiCo-LDH core-shell NWAs is attributed to the enhanced charge transfer and separation, resulting from the decoration of the NiCo-LDH cocatalyst. This facile and cost-effective strategy for integrating the light-harvesting TiO2 semiconductor and NiCo-LDH cocatalyst into a hierarchical core-shell nanostructure can be potentially applied in energy conversion and environmental applications.

V2O5 nanosheets supported on 3D N-doped carbon nanowall arrays as an advanced cathode for high energy and high power fiber-shaped zinc-ion batteries

A 3D hierarchical core–shell nanostructure was designed as an advanced cathode for high energy and high power fiber-shaped Zn-ion batteries.

Advanced three-dimensional hierarchical Pr6O11@Ni-Co oxides-based core-shell electrodes for supercapacitance application

A facile solvothermal method is used to fabricate hierarchical core-shell nanostructures based on praseodymium, nickel and cobalt oxides supported on nickel foam. The Pr6O11 nanoparticles were first grown on the nickel foam and then utilized as a backbone for anchoring NiO, Co3O4 and NiCo2O4 nanostructures to form a core-shell structure. The core-shell electrodes exhibit superior electrochemical performance than single Pr6O11 nanoparticles electrodes. A superior specific capacitance of 1635 F/g at a current density of 0.5 mA/cm2 with good cycling stability was obtained for the Pr6O11@NiCo2O4 electrode. Moreover, a solid-state supercapacitor was fabricated by assembling Pr6O11@NiCo2O4 electrodes using KOH/PVA as the solid electrolyte. The as-prepared solid-state device demonstrated impressive energy density of 6.6 W h/kg and a power density of 150 W/kg. This optimal performance could be attributed to the high conductive nickel foam current collector and synergistic effects generated from the core-shell architecture of NiCo2O4 and the Pr6O11 nanoparticles.