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Rationally designing and engineering electrodes with multiple components and favorable architectures is an effective way to modulate their electrochemical performance. Here, we present the tailored synthesis of a novel 3D macroporous electrode with hierarchical lollipop-like MnCo2S4/FeCo2S4 heterostructures immobilized on a flexible N-doped carbon matrix, which delivers a high specific capacitance of 2806 F g−1 (capacity of 1403 C g−1) at 1 A g−1 and excellent cycling stability (85.1% of its initial value after 5000 cycles). Moreover, a hybrid supercapacitor device based on the self-supported MnCo2S4/FeCo2S4/N-CMF electrode achieves a high energy density of 87.3 W h kg−1 at a power density of 799.9 W kg−1 and great electrochemical stability under bending conditions. This remarkable capacitive performance is attributed to the collaborative contribution from three components involving the enhanced charge transfer on the 3D interconnected carbon matrix, the unique ion-diffusion "short-cuts" provided by the hollow interior of the carbon skeleton, the abundant void space and electroactive sites in sheet-built MnCo2S4 spheres and rough FeCo2S4 nanoneedles, and great structural stability of firmly connected MnCo2S4/FeCo2S4 "lollipops". Thus, this work offers insight into the rational construction of transition metal sulfide complexes for next-generation high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Developing highly active, stable and robust electrocatalysts based on earth‐abundant elements for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is important for many renewable energy conversion processes. Herein, NixCo3‐xO4 nanoneedle arrays grown on 3D porous nickel foam (NF) was synthesized as a bifunctional electrocatalyst with OER and HER activity for full water splitting. Benefiting from the advantageous structure, the composite exhibits superior OER activity with an overpotential of 320 mV achieving the current density of 10 mA cm−2. An exceptional HER activity is also acquired with an overpotential of 170 mV at the current density of 10 mA cm−2. Furthermore, the catalyst also shows the superior activity and stability for 20 h when used in the overall water splitting cell. Thus, the hierarchical 3D structure composed of the 1D nanoneedle structure in NixCo3‐xO4/NF represents an avenue to design and develop highly active and bifunctional electrocatalysts for promising energy conversion. Nanocatalysis: NixCo3‐xO4 nanoneedle arrays grown on Ni foam were synthesized and acted as an efficient bifunctional electrocatalyst for full water splitting. [ABSTRACT FROM AUTHOR]

Controllable synthesis of uniform graphene–metal oxide nanocomposites is of great interest in energy storage applications, due to the combination of their merits and the synergistic effects on the enhancement of their electrochemical performance. Herein, we report a controllable synthesis of uniform mesoporous H-Nb2O5/rGO nanocomposites, which exhibit higher reversible specific capacity (∼190 mA h g−1), and better rate capability and cycling stability (the capacitance retention is 96.5% over 500 cycles) than pristine H-Nb2O5 microflowers, attributed to their large specific surface area (364.17 m2 g−1), porous structure, and intimate interface. More remarkably, the H-Nb2O5/rGO-based lithium ion hybrid supercapacitor (LIHS) delivered a high energy density of 100.2 W h kg−1 at 50 W kg−1 and still retained 18.3 W h kg−1 at an ultrahigh power density of 20 000 W kg−1, as well as an excellent cycling stability. It is worth noting that some other nanocomposites, including Zn2Ti3O8/rGO, Si/rGO, NaNbO3/rGO, Nb4N5/rGO, and H-Nb2O5/2D g-C3N4, have also been successfully synthesized by this method, demonstrating that it can be extended to prepare other functional nanocomposites for applications in energy conversion and storage, photocatalytic hydrogen production, sensors, and so on. [ABSTRACT FROM AUTHOR]

The ever‐increasing global demand for green energy resources calls for more research attention on the development of cheap and efficient energy storage systems. Herein, we propose the rational design of a 3D carbon foam electrode deposited with perpendicularly oriented FeCo2S4 nanotubes arrays (FeCo2S4/CMF) for high‐performance asymmetric supercapacitors. In this work, the macroporous CMF served as conducting backbone not only to enhance the electrical conductivity of the composite, but also to promote the uniform growth of FeCo2S4 nanotubes. Deposited hierarchical FeCo2S4 nanotubes arrays with open hollow structures can afford numerous exposed electroactive sites for Faradaic redox reaction and provide short interior channels for fast electrolyte transmission. Due to these unique features, obtained 3D hierarchical FeCo2S4/CMF composite foam exhibits a high specific capacitance of 2430 F g−1 (specific capacity of 337.5 mAh g−1) at 1 A g−1, and excellent capacitance retention of 91 % after 5000 cycles at a high current density of 9 A g−1, which is superior to most of those previously reported binary metal sulfide‐based electrodes. Moreover, asymmetric supercapacitor device assembled using the FeCo2S4/CMF as positive electrode also delivers a high energy density of 78.7 W h kg−1 at a power density of 800.3 W kg−1. Therefore, this work provides a new strategy for the low‐cost synthesis of 3D foam electrodes towards high‐performance supercapacitor devices. Rough and ready: Perpendicularly oriented FeCo2S4 nanotubes arrays with well‐defined hollow channels and rough shells were deposited on a 3D carbon skeleton through a versatile two‐step sulfidation process, benefiting from the joint advantages of sufficient electrochemical active sites and conducting carbon networks. The obtained composite foam exhibits a superior capacitive performance as compared to previously reported binary metal sulfide‐based electrodes. [ABSTRACT FROM AUTHOR]

A 3D hierarchical NiCo2O4/PANI/MF composite foam with a macroporous 3D skeleton, a conductive PANI coating and highly electrochemically active NiCo2O4 nanosheets is synthesized as a lightweight and low-cost electrode material. Due to the collaborative contribution of all the components, the prepared composite foam exhibits excellent capacitive performances when incorporated into an asymmetric supercapacitor. [ABSTRACT FROM AUTHOR]

Wearable electronics with conductive yet stretchable bio-interfaces, multimodal health regulating capabilities, and strong weather resistance are especially expected by athletes and outdoor workers, yet conventional rigid, impermeable, and monofunctional wearables can hardly meet these requirements simultaneously. Here, a hierarchical and ultrastretchable all-in-one health-regulating electronic textile (AIO E-textile) with robust superhydrophobic and antibacterial surfaces is developed through electrospin-assisted layer-by-layer assembly and liquid metal (LM) printing. Skin-like and bio-compatible styrene-ethylene-butylene-styrene (SEBS) nonwoven textile is employed as a breathable matrix for the layered E-textile, in which an electrophysiological recording circuit, a strain-sensing circuit, and a Joule heating circuit are successively patterned using EGaIn. To ensure human skin health and weather resistance of the device, antibacterial and waterproof surfaces are respectively installed on both sides of the electronic textile via anchoring functionalized nanoparticles. Thus, this ultrastretchable (1141 %) AIO E-textile shows favorable moisture permeability (1300 g m−2 day), exceptional water repellency, remarkable antibacterial efficacy (>99.99 %) against E-coli , and low-watt Joule heating ability, which even exhibits accurate under-water motion detection capability, and high-definition acquiring of bioelectrical signals (electrocardiogram (ECG) and surface electromyography (sEMG)) when used as flexible epidermal bioelectrode. This work opens up a new avenue for daily applicable and multifunctional on-skin electronics. [Display omitted] • A hierarchical all-in-one health-regulating electronic textile is constructed. • Antibacterial and waterproof surfaces are installed by anchoring nanoparticles. • Multifunctional liquid metal circuits are printed for multimodal health regulating. • The E-textile can be used for under-water motion detection and joule heating. • Multiple bioelectrical signals can be accurately monitored by the AIO E-textile. [ABSTRACT FROM AUTHOR]

Exploring non-precious-metal-based oxygen reduction reaction (ORR) electrocatalysts featuring high efficiency, low cost, and environmental friendliness is of great importance for the broad applications of fuel cells and metal-air batteries. In this work, ultrathin NiCo2O4 nanosheets deposited on 1D SnO2 nanotubes (SNT) were successfully fabricated through a productive electrospinning technique followed by a sintering and low-temperature coprecipitation strategy. This hierarchically engineered architecture has ultrathin NiCo2O4 nanosheets uniformly and fully erected on both walls of tubular SNTs, which results in improved electrochemical activity as an ORR catalyst, in terms of positive onset potential and high current density, as well as superior tolerance to crossover effects and long-term durability with respect to the commercial Pt/C catalyst. The excellent performance of SNT@NiCo2O4 composites may originate from their rationally designed hierarchical tubular nanostructure with completely exposed active sites and interconnected 1D networks for efficient electron and electrolyte transfer; this makes these composite nanotubes promising candidates to replace platinum-based catalysts for practical fuel cell and metal-air battery applications. [ABSTRACT FROM AUTHOR]

The development of platinum-free electrocatalyst for hydrogen evolution reaction (HER) is highly essential to the large-scale production and application of water splitting devices. Herein, a novel type of molybdenum diselenide decorated porous carbon fiber (MoSe2-PCF) composite has been reported for HER. Notably, the unique mesoporous structure of electrospun polystyrene (PS) fibers is perfectly duplicated via the in situ self-polymerization of dopamine by using PS fibers as the hard template, while porous carbon fibers are formed after the subsequent thermal annealing of polydopamine-coated PS fibers. Thus obtained porous carbon fibers exhibit largely improved surface area which could provide highly conductive framework for electron transport, being an ideal substrate for the decoration of MoSe2. With maximally exposed active edge sites from the perpendicularly orientated MoSe2 nanosheets, the MoSe2-PCF composite exhibits high catalytic activity toward HER, holding great potentials as highly efficient metal-free electrodes for energy related applications. [ABSTRACT FROM AUTHOR]

The prosperity of wearable and healthcare electronics yearns for the compact integration of multi-functionalities including detectability for various electrophysiological signals, thermal/moisture management, and electromagnetic wave protection. Herein, highly breathable and ultrastretchable styrene-ethylene-butylene-styrene (SEBS)-Ag-liquid metal (SSLM) nonwoven electronic textiles are fabricated as versatile on-skin bioelectrodes for accurate health monitoring, Joule heating, and electromagnetic interface (EMI) shielding. Taking advantage of the reactive alloying between liquid metal and magnetron sputtered silver nanoparticles, ultra-conductive eutectic gallium-indium (EGaIn) is intimately and uniformly encapsulated on superlyophilic SEBS microfibers after activation via monolithic pre-stretching. Benefiting from the highly deformable, extremely stable, and 3D interconnected conducting networks, the nonwoven E-textiles demonstrate exceptional EMI shielding effectiveness (75.3 dB at frequencies of 8.2–12.8 GHz, and still maintain 31.7 dB at 300% elongation), and efficient Joule heating performance also under large-scale deformation (120%). Moreover, the breathable SSLM E-textiles used as skin-attachable bioelectrodes even manifest prominent monitoring performance for biophysical signals (breath, phonation, and joint bending), surface electromyography signals (sEMG), and electroencephalogram signals (EEG). Therefore, the superlyophilicity and superior performance of the liquid metal E-textiles enable a wide range of applications in next-generation skin electronics and protective textiles. [Display omitted] • The electronic textile has superlyophilicity to liquid metal due to the fast alloying. • monolithic stretch activation is used to recover the breathability of liquid metal textile. • obtained electronic textile has a high conductivity upon 1000% elongation. • the electronic textile shows efficient EMI shielding and Joule heating performance. • the electronic textile can monitor human biophysical and bioelectrical signals. [ABSTRACT FROM AUTHOR]

It is universally acknowledged that the development of high-efficiency Pt-free electrocatalysts for hydrogen evolution reaction (HER) is a challenging and demanding task nowadays. Herein, graphene wrapped carbon nanofiber @ molybdenum disulfide (GCNF@MoS 2 ) hybrids with hierarchical structure have been successfully prepared as HER electrocatalysts through the combination of electrospinning, solution soaking and solvothermal methods. The wrapping of few-layered graphene functions crucially as a “bridge” closely linking three-dimensional (3D) carbon nanofibers and electrocatalytically active MoS 2 , providing a highly conductive pathway through the whole hybrids, thus facilitating the transport of electrons. Furthermore, carbon nanofibers acting as “spacers” between graphene layers can efficiently impede their restacking, thus giving full play to the superior electrical conductivity of graphene. Benefiting from the 3D network and template of GCNF, MoS 2 nanosheets can grow densely and perpendicularly on the fiber surface, therefore exposing catalytically active edges effectively. Owing to the synergistic effects among three components, the GCNF@MoS 2 hybrid exhibits remarkable electrocatalytic activity with a low onset potential of −0.08 V, a small Tafel slope of 49.6 mV per decade, a large current density (10.0 mA cm −2 at η = 0.15 V) as well as excellent stability. Apart from fabricating an efficient HER catalyst, this work also provides a practical strategy for designing hybrid materials with multi-functions for their potential applications in new energy field. [ABSTRACT FROM AUTHOR]