Complex Hollow Structures Research Articles

RuCo@C Hollow Nanoprisms Derived from ZIF-67 for Enhanced Hydrogen and Oxygen Evolution Reactions.

Zeolitic imidazolate frameworks (ZIFs) are commonly used to create complex hollow structures for energy applications. This study presents a simple method to produce a novel hollow nanoprism Co@C hierarchical composite from ZIF-67 through high-temperature treatment at 800 °C. This composite serves as a platform for Ru nanoparticle deposition, forming RuCo@C hollow nanoprism (RuCo@C HNP). As an electrocatalyst in 1 M KOH, RuCo@C HNP exhibits excellent hydrogen evolution reaction (HER) performance, with a low overpotential of 32 mV to reach 10 mA cm-2, a Tafel slope of 39.67 mV dec-1, a high turnover frequency (TOF) of 3.83 s-1 at ƞ200, and stable performance over 50 h. It also achieves a low ƞ10 of 266 mV for the oxygen evolution reaction (OER) with a Tafel slope of 45.22 mV dec-1. Density functional theory (DFT) calculations reveal that Ru doping in Ni/Co maintains a low water dissociation barrier, reduces the energy barrier for the OER rate-determining step, and creates active sites for H*, enhancing adsorption/desorption abilities. These results are attributed to the synergy between Co and Ru and the hollow prism structure's increased surface area. This method for synthesizing hollow structures using ZIF composites shows promise for applications in the energy sector.

Study on the Mechanical Properties of 3D-Printed Sand Mold Specimens with Complex Hollow Structures.

Casting, as a fundamental process in metal forming, finds widespread applications in the manufacturing industry. The advent of 3D printing hollow sand mold technology presents a novel method for casting technology to revolutionize traditional dense sand molds, offering increased flexibility in achieving quality control and improvement in casting processes. Consequently, this study delves into an examination of the mechanical strengths of 3D-printed sand molds with complex hollow structures and further investigates the influence of hollow sand mold concession on castings. The results indicate that compressive and high-temperature residual tensile and bending strengths vary in hollow structures. Multi-layer shells have greater high-temperature residual tensile, compressive, and bending strengths than truss hollow sand molds with roughly the same hollow volume fraction. Compared to dense sand molds, hollow sand molds, which have a lower mechanical strength, have better retractability, which helps reduce the residual stress and crack tendency of castings. The breaking of hollow structures is limited to local areas, unlike the penetrative cracking of dense sand molds. The I-beam-shaped casting test results indicate that a hollow structure is beneficial for the preservation of the integrity of a sand mold during the casting process. Compared to dense and truss hollow molds, a multi-layer shell hollow sand structure has the comprehensive advantages that it improves retractability while maintaining strength relatively well, reduces the residual stress, and avoids cracks in castings and itself.

ZIF-derived hollow cattail-shaped composites with hierarchical channels towards enhanced electrochemical properties for supercapacitors

Despite the achievement in generating various hollow architectures, designing hollow composites with hierarchical channels remains challenging to achieve excellent electrochemical energy storage performance. To address this issue, we developed an in situ self-assembly strategy to prepare hollow composites using zeolitic-imidazolate frameworks and carbon nanotubes (ZIF@CNT). These ZIF@CNT architectures with different appearances are prepared by adjusting the stirring rate during the reaction. Subsequently, the sulfurization strategy is applied to convert ZIF-67 to cobalt sulfide (CoS), resulting in the hollow CoS@CNT hybrids. These hierarchical channels include the hollow CoS cavities and CNT channels. The unique hollow composites with different dimensions played a synergistic effect between subunits, thus giving excellent electrochemical properties. The impact of particle cavity channel size on electrochemical properties was evaluated systematically. As expected, CoS@CNT with hollow cattail-shape structures (HCCoS@CNT) resulted in the optimal specific capacitance (1250 F/g) and cyclic stability (90.4 % for over 10,000 times of cycling at 10 A/g). The designed hybrid supercapacitor, HCCoS@CNT//active carbon (AC), delivered an exceptional energy density of 40 Wh kg−1 at 800 W kg−1 of the power density. Together, these findings provide a reference for preparing complex hollow structures as high-performance electrodes, clarifying the optimization of composites for improved electrochemical properties.

Colloidal tubular microrobots for cargo transport and compression

Microrobot swarms have seen increased interest in recent years due to their potentials for in vivo delivery and imaging with cooperative propulsion modes and enhanced imaging signals. Yet most swarms developed so far are limited to dense particle aggregates, far simpler than complicated three-dimensional assemblies of anisotropic particles. Here, we show via assembly path design that complex hollow tubular structures can be assembled from simple isotropic colloidal spheres and those complicated, metastable, microtubes can be formed from simple, energetically favorable colloidal membranes. The assembled microtubes can remain intact and roll under a precessing magnetic field, with propulsion directions and velocities precisely controlled by field components. The hollow spaces inside enable these tubular microrobots to grab, transport, and release cargos on command. We also demonstrate unique compressing and uncompressing capabilities with our tubular microrobots, making them effective microtweezers. Our work shows that complicated microrobots can be transformed from simple assemblies, providing an insight on building micromachines.

Reinforcement of silica-based ceramic cores based on amorphous and polycrystalline mullite fibers

In the investment casting of turbine blades, ceramic cores are key components to form complex hollow structures. Superior mechanical property and leaching rate are demanded for ceramic cores. Herein, ceramic cores were fabricated using fused silica powders as the matrix, and amorphous and polycrystalline mullite fibers as the reinforcement phases, respectively. The microstructure and property evolution of ceramic cores rely on the crystallization degree of mullite fibers are explored. Both of the mullite fibers lead to improved crystallization of cristobalite, reduced sintering shrinkage, increased apparent porosity, and benefited bending strength, creep resistance, and leaching rate of the cores. Compared to the polycrystalline mullite fibers, the amorphous fibers are metastable with large quantities of structural defects, promoting the diffusion mass transfer and forming strong interface between fibers and matrix. Therefore, the amorphous fibers have larger promotion on the bending strength and resistance to creep deformation of ceramic cores. Moreover, the structural defects of amorphous fibers ensures the high chemical activity in alkaline solutions and exhibits excellent leaching rate. The ceramic core with 4.5 wt% of amorphous mullite fibers exhibits excellent comprehensive performance with bending strengths of 28.9 MPa and 23.8 MPa at room temperature and 1550 °C, creep deformation of 0.3 mm, and leaching rate of 1.4 g/min, well meeting the casting requirements of hollow blades.

Amorphous and defective Co-P-O@NC ball-in-ball hollow structure for highly efficient electrocatalytic overall water splitting

Electrochemical water splitting using hollow and defect-rich catalysts has emerged as a promising strategy for efficient hydrogen production. However, the rational design and controllable synthesis of such catalysts with intricate morphology and composition present significant challenges. Herein, we propose a template-engaged approach to fabricate a novel ball-in-ball hollow structure of Co-P-O@N-doped carbon with abundant oxygen vacancies. The synthesis process involves the preparation of uniform cobalt-glycerate (Co-gly) polymer microspheres as precursors, followed by surface coating with ZIF-67 layer, adjustable chemical etching by phytic acid, and controllable pyrolysis at high temperature. The resulting ball-in-ball structure offers a large number of accessible active sites and high redox reaction centers, facilitating efficient charge transport, mass transfer, and gas evolution, which are beneficial for the acceleration of electrocatalytic reaction. Additionally, density functional theory (DFT) calculations indicate that the incorporation of oxygen and the presence of Co-P dangling bonds in CoP significantly enhance the adsorption of oxygenated species, leading to improved intrinsic electroactivity at the single-site level. As a sequence, the titled catalyst exhibits remarkable electrocatalytic activity and stability for water splitting in alkaline media. Notably, it only requires a low overpotential of 283 mV to achieve a current density of 10 mA cm−2 for the oxygen evolution reaction. This work may provide some new insights into the design of complex hollow structures of phosphides with abundant defects for energy conversion.

Oriented Design of Transition-Metal-Oxide Hollow Multishelled Micropolyhedron Derived from Bimetal–Organic Frameworks for the Electrochemical Detection of Multipesticide Residues

Transition-metal oxides (TMOs) with a hollow multishelled structure have emerged as highly potential materials for high-performance electrochemical sensing, benefiting from their superior electronic conductivity, exceptionally large specific surface area, excellent stability, and electrochemistry properties. In particular, binary TMOs are expected to outperform unitary TMOs due to the synergistic effect of the different metals. Herein, MnCo2O4.5 hollow quadruple-shelled porous micropolyhedrons (MnCo2O4.5 HoQS-MPs) were prepared and employed to construct an ultrasensitive sensing platform for a multipesticide assay. Profiting from complex hollow interior structures and abundant active sites, the MnCo2O4.5 HoQS-MPs manifest outstanding electrochemical properties as electrode materials for the pesticide assay. The MnCo2O4.5 HoQS-MP-based biosensor demonstrated remarkable performance for monocrotophos, methamidophos, and carbaryl detection, with wide linear ranges, as well as low detection limits. This work unveils a new pathway for the ultrasensitive detection of pesticides and demonstrates tremendous potential for detecting other environmentally deleterious chemicals.

Biofabricating the vascular tree in engineered bone tissue.

The development of tissue engineering strategies for treatment of large bone defects has become increasingly relevant, given the growing demand for bone substitutes. Native bone is composed of a dense vascular network necessary for the regulation of bone development, regeneration and homeostasis. A major obstacle in fabricating living, clinically relevant-sized bone mimics (1-10 cm3) is the limited supply of nutrients, including oxygen to the core of the construct. Therefore, strategies to support vascularization are pivotal for the development of tissue engineered bone constructs. Creating a functional bone construct integrated with a vascular network, capable of delivering the necessary nutrients for optimal tissue development is imperative for translation into the clinics. The vascular system is composed of a complex network that runs throughout the body in a tree-like hierarchical branching fashion. A significant challenge for tissue engineering approaches lies in mimicking the intricate, multi-scale structures consisting of larger vessels (macro-vessels) which interconnect with multiple sprouting vessels (microvessels) in a closed network. The advent of biofabrication has enabled complex, out of plane channels to be generated and has laid the groundwork for the creation of multi-scale vasculature in recent years. This review highlights the key state-of-the-art achievements for the development of vascular networks of varying scales in the field of biofabrication with a particular focus for its application in developing a functional tissue engineered bone construct. STATEMENT OF SIGNIFICANCE: There is a growing need for bone substitutes to overcome the limited supply of patient-derived bone. Bone tissue engineering aims to overcome this by combining stem cells with scaffolds to restore missing bone. The current bottleneck in upscaling is the lack of an integrated vascular network, required for the delivery of nutrients to cells. 3D bioprinting techniques has enabled the creation of complex hollow structures of varying dimensions that resemble native blood vessels. The convergence of multiple materials, cell types and fabrication approaches, opens the possibility of developing clinically-relevant sized vascularized bone constructs. This review provides an up-to-date insight of the technologies currently available for the generation of complex vascular networks, with a focus on their application in bone tissue engineering.

High performance hybrid supercapacitors assembled with multi-cavity nickel cobalt sulfide hollow microspheres as cathode and porous typha-derived carbon as anode

Unique hollow structures hold bright promise in the field of energy storage applications, but it is still challenging to synthesize bimetallic sulfide composites with complex hollow structures. In the present work, a NixCo1−xS2/NiCo2S4 composite with multi cavity hollow sphere structure is prepared by a simple liquid-phase reaction and solvothermal sulfurization and used as a supercapacitor positive electrode material. Benefiting from the well-designed unique structure and synergy between the nickel and cobalt elements, the composite exhibits excellent electrochemistry with a specific capacity of 797 C g−1 at 1 A g−1 and possesses good rate capability (78.8 % retention at 20 A g−1). In addition, Typha-derived carbon is prepared by calcination using discarded biomass Typha. And, a hybrid supercapacitor device is assembled by using NixCo1−xS2/NiCo2S4 and Typha-derived carbon as cathode and anode. The device exhibits a high energy density of 82.7 Wh kg−1 at 513.5 W kg−1 and possesses superior long-term cycling capacity (84.6 % after 10,000 cycles), indicating the great application potential of the composites in the field of supercapacitors. More importantly, the unique structural design and facile operation methods provide new ideas and broad prospects for the synthesis of complex metal sulfide materials in the energy storage field later.

Designing of aluminium case lid of prismatic battery cell for laser powder bed fusion

The present work provides an overview on an additive manufacturing (AM) design case of a novel battery cell lid structure (patent pending) for electrical vehicle applications. The benefits of AM have not yet been explored on metal case structures of prismatic battery cells. The method allows the manufacturing of complex hollow structures and integration of multiple functions in one part. The main challenge is to address thermal management in an optimal location in the battery cell. More efficient charging and discharging by maintaining the batteries at optimum operating conditions allows a longer battery lifetime. Recent research shows that elevating the charging temperature enables significantly shorter charging times. The aim of this study is to develop a lid structure to support higher peak current, faster charging, and reduced production steps and enable mass customization. The optimum performance simulated with computational fluid dynamics calculations is realized to determine the optimum design. The design case study is verified via laser powder bed fusion prototypes. This study shows that it is possible to produce integrated thermal management liquid channels to the battery lid. Significant improvement is achieved with localized battery cell temperature management. The novel design integrates six critical functionalities of the lid in one part. The design of the features is optimized to avoid support structures in AM and to maximize the number of parts in the printing chamber volume. The better thermal management extends the driving range of the vehicle and improves vehicle safety. Reducing the parts significantly simplifies cell production.

Engineering of MoSe2 decorated Ni/Co selenide complex hollow arrayed structures with dense heterointerfaces for high-performance aqueous alkaline Zn batteries

The development of advanced Ni/Co-based cathode electrodes for aqueous alkaline Zn batteries (AZBs) is highly desirable, but still remains a challenging task. Herein, we rationally design and synthesize the unique MoSe2 decorated Ni/Co selenide complex hollow arrayed structures (CH-MNCS) with dense heterointerfaces supported on nickel foam (NF) through a metal–organic framework-engaged strategy, in which heterostructured CoSe/MoSe2 hollow nanocages are uniformly assembled on heterostructured NiSex/MoSe2 nanotubes. Benefiting from the apparent morphological, structural and compositional advantages, aqueous AZBs based on the NF/CH-MNCS binder-free cathode exhibit high areal capacity and energy density of 1.42 mAh cm−2 and 2.45 mWh cm−2 at a current density of 2 mA cm−2, respectively, as well as decent rate capability and long cycling stability. Furthermore, density functional theoretical calculations further confirm the presence of heterointerfaces can not only enhance the electrical conductivity but also facilitate the adsorption of OH− ions in the electrolyte. More importantly, the quasi-solid-state NF/CH-MNCS//Zn batteries are also assembled to demonstrate the potential for practical applications. This work may provide a new perspective to construct heterostructured transition metal selenide complex hollow structures on conductive substrate for aqueous AZBs and other energy storage devices.

Smart construction of MnCo2O4 microspheres with multiple interiors: Morphological evolution and structure-performance relationship for supercapacitor electrodes

The development of a simple and general approach for manufacturing complex hollow structures is essential to achieve rapid dynamic response and high energy density storage for supercapacitor electrodes. Herein, we report a versatile heating rate-controlled synthetic route to prepare MnCo2O4 microspheres with multiple interiors. Comparative study reveals that MnCo2O4 microspheres with core–shell structure (MCO-CSS) process the highest specific surface area (91.6 m2 g−1) and oxygen vacancy density (0.16), which can provide more electroactive sites for surface Faradic reaction and further facilitate the kinetics of rapid charge storage. While the porous shell and well-defined gap endow MCO-CSS with excellent permeability and low-resistance pathways for electrolyte ions, as well as enhanced volume change accommodation. Benefiting from the structural advantages, MCO-CSS displays an excellent specific capacitance of 1064.4F g−1 at 1 A g−1, remarkable rate capability, and satisfactory cycle stability (89.1% capacitance retention at 2 A g−1 over 1000 cycles). Additionally, an asymmetric supercapacitor device, with an MCO-CSS cathode and porous carbon spheres anode, delivers a remarkable energy density of 33.9 Wh kg−1 at a power density of 187.4 W kg−1, as well as 84.13% capacitance retention over 3000 cycles at 1 A g−1.

In Situ Growth of Three‐Dimensional MXene/Metal–Organic Framework Composites for High‐Performance Supercapacitors

AbstractIn this study, we propose a versatile method for synthesizing uniform three‐dimensional (3D) metal carbides, nitrides, and carbonitrides (MXenes)/metal–organic frameworks (MOFs) composites (Ti3C2TX/Cu‐BTC, Ti3C2TX/Fe,Co‐PBA, Ti3C2TX/ZIF‐8, and Ti3C2TX/ZIF‐67) that combine the advantages of MOFs and MXenes to enhance stability and improve conductivity. Subsequently, 3D hollow Ti3C2TX/ZIF‐67/CoV2O6 composites with excellent electron‐ and ion‐transport properties derived from Ti3C2TX/ZIF‐67 were synthesized. The specific capacitance of the Ti3C2TX/ZIF‐67/CoV2O6 electrode was 285.5 F g−1, which is much higher than that of the ZIF‐67 and Ti3C2TX/ZIF‐67 electrode. This study opens a new avenue for the design and synthesis of MXene/MOF composites and complex hollow structures with tailorable structures and compositions for various applications.

In Situ Growth of Three‐Dimensional MXene/Metal–Organic Framework Composites for High‐Performance Supercapacitors

In this study, we propose a versatile method for synthesizing uniform three-dimensional (3D) metal carbides, nitrides, and carbonitrides (MXenes)/metal-organic frameworks (MOFs) composites (Ti3 C2 TX /Cu-BTC, Ti3 C2 TX /Fe,Co-PBA, Ti3 C2 TX /ZIF-8, and Ti3 C2 TX /ZIF-67) that combine the advantages of MOFs and MXenes to enhance stability and improve conductivity. Subsequently, 3D hollow Ti3 C2 TX /ZIF-67/CoV2 O6 composites with excellent electron- and ion-transport properties derived from Ti3 C2 TX /ZIF-67 were synthesized. The specific capacitance of the Ti3 C2 TX /ZIF-67/CoV2 O6 electrode was 285.5 F g-1 , which is much higher than that of the ZIF-67 and Ti3 C2 TX /ZIF-67 electrode. This study opens a new avenue for the design and synthesis of MXene/MOF composites and complex hollow structures with tailorable structures and compositions for various applications.

General Strategy for Fabrication of Ordered One Dimensional Inorganic Structures by Electrospinning: Structural Evolution From Belt to Solid via Hollow Tubes

Super‐structured hollow materials are the subject of intense research due to their attracting properties and diverse applications. Despite their significance, it still remains a crucial challenge to develop a simple and well‐organized method to prepare the hollow tubes with controlled architectures. Herein, a general route to prepare structurally well‐defined 1D zinc oxide (ZnO) structures by a single‐spinneret electrospinning method coupled with thermal treatment is demonstrated for the first time and subsequently designated to identify high‐performance materials for catalytic application. Two critical factors including tailoring the precursor amount and colloidal‐stability of the precursor play critical role in tuning the structure precisely. The careful optimization of processing conditions enables chronological structural evolution from tubular to solid fiber structures composed of nanograins. These ZnO complex hollow structures showcase excellent photocatalytic performance; single nanograined wall hollow tubes manifest the high‐catalytic performance over other samples with remarkable cycling stability. Benefitting from fabrication adaptability, different types of metal oxide hollow tubes are prepared that indicates the generality of the method. The proposed method postulates new insights for the development of electrospun hollow‐structured fibers in a simple, cost‐effective, and industrially feasible manner which holds apparent potential in many sectors.

Construction of complex copper-cobalt selenide hollow structures as an attractive battery-type electrode material for hybrid supercapacitors

The application of battery-like electrode materials with complex hollow structures, huge surface areas, and good redox properties is an appealing approach towards the boosting performance of hybrid supercapacitors. This work proposes a facile strategy for the fabrication of copper-cobalt selenide hollow spheres (CCSe-HSs) as a new battery-type electrode for hybrid supercapacitors. Benefiting from the considerable electrical conductivity and rationally porous structures, this electrode exhibits a higher capacitance/capacity of 1775.4F g−1/295.9 mAh g−1 compared with copper-cobalt sulfide hollow spheres (CCS-HSs) and copper-cobalt oxide hollow spheres (CCO-HSs). Besides, an advanced device (CCSe-HSs//AC) constructs by combining copper-cobalt selenide hollow spheres (positive electrode) and activated carbon (AC, negative electrode). Our device reflects reasonable energy and power densities (53.86 W h kg−1 at 800 W kg−1, respectively), and desirable cyclability. Our current study provides a rationale and efficient design strategy to engineer new bimetallic selenides with complex hollow structures for different applications.

Formation of NiCo2O4 hierarchical tubular nanostructures for enhanced xylene sensing properties

Complex hollow structures with ultra-thin 2D building blocks represent a unique type of functional nanostructures because of their structural merits. In this work, hierarchical NiCo2O4 hollow microtubules assembled by ultra-thin 2D nanosheets have been successfully prepared via a template-assisted process with subsequent etching treatment. The purity, morphology, crystallographic information and surface chemical composition of as-obtained hierarchical NiCo2O4 hollow microtubules are characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM), element mapping, X-ray photoelectron spectroscopy (XPS) and Nitrogen adsorption–desorption analysis. Gas sensing performance of hierarchical NiCo2O4 hollow microtubules is discussed in detail. The results show that hierarchical NiCo2O4 hollow microtubules not only exhibit rapid response/recovery (20/9 s) speed to 100 ppm xylene at relatively low working temperature of 220 °C, but also show low detection limit (1 ppm), high response, excellent gas selectivity and superior long-term stability, which are significantly better than irregular NiCo2O4 nanosheets. The results demonstrate that unique hierarchical NiCo2O4 hollow microtubules are promising candidates for efficient and reliable detection of xylene.

A novel ball-in-ball hollow oxygen-incorporating cobalt sulfide spheres as high-efficient electrocatalyst for oxygen evolution reaction

Transition-metal chalcogenides with hollow nanostructure, especially cobalt sulfides, are considered as the most promising non-precious metal catalysts for oxygen evolution reaction. However, it is difficult to synthesize oxygen-containing cobalt sulphides with hollow structure due to the different physical/chemical properties between metal sulfides and metal cobalts. Herein, we report a novel oxygen-containing amorphous cobalt sulfide ball-in-ball hollow spheres (Co-S-O BBHS) synthesized by an anion exchange method. Taking advantage of the ball-in-ball hollow structure, the amorphous Co-S-O BBHS shows superior oxygen evolution reaction (OER) electrocatalytic performance with a low overpotential of 285 mV at 10 mA/cm2, small Tafel slope of 49.67 mV/dec, high Faraday efficiency of 96%, and satisfied durability. Experiments and DFT calculations demonstrate that the introduction of oxygen and sulfur modulates the electronic structure of Co-S-O BBHS, thus enhancing the adsorption of *O (adsorbed O species on catalyst surface) intermediate, which greatly boosts the catalytic activity towards OER. This work provides a new strategy for controllable synthesis of complex hollow structures of transition-metal chalcogenides for OER.

Complex Hollow Structures of Cobalt(II) Sulfide as a Cathode for Lithium–Sulfur Batteries

Complex Hollow Structures of Cobalt(II) Sulfide as a Cathode for Lithium–Sulfur Batteries

Construction of sugar gourd-like yolk-shell Ni–Mo–Co–S nanocage arrays for high-performance alkaline battery

Mixed transition metal sulfides (TMSs) with hollow and complex hollow structures have attracted intensive attentions as high-performance cathode materials for rechargeable alkaline batteries. However, these powder-based electrode materials should be further mixed with insulative polymer binders and suffered from complicate electrode fabrication process. Herein, for the first time, we demonstrate the delicate design and synthesis of the sugar gourd-like multi-component yolk-shell Ni–Mo–Co–S nanocage arrays (NCAs) on Ni foam (NF) through a facile metal-organic framework (MOF)-engaged strategy. The synthetic process includes the growth of Co-based zeolitic imidazolate framework (ZIF-67) polyhedra onto the NiMoO4·xH2O nanorod arrays (NRAs) at room temperature and followed by a sufficient sulfidation reaction. Benefiting from the intriguing structural and compositional advantages, the yolk-shell Ni–Mo–Co–S NCAs/NF binder-free electrode exhibits an extremely high areal capacity of 1.96 mAh cm−2 at a current density of 5 mA cm−2 and excellent cycling stability. The electrode kinetics analysis confirms the diffusion-controlled battery-type behavior of the yolk-shell Ni–Mo–Co–S NCAs/NF electrode. The corresponding full cell delivers an high energy density of 92.6 Wh kg−1 at the power density of 1029.1 W kg−1 with the yolk-shell Ni–Mo–Co–S NCAs/NF as cathode electrode and Bi2O3 as anode electrode, indicating the potential for real applications. This work would make contribution to the realization of directly growing multi-component hollow and complex hollow structures on conductive substrate for high-performance electrochemical energy storage.