Search

We synthesized ultrafine Mn 2 O 3 quantum dots embedded into N-doped carbon to generate two-dimensional (2D) composites (MNC) with robust interfacial heterostructural interactions (C O Mn bonds) via a facile solvent-free tactics, which could enhance the Na+-storage properties with the fast kinetics, superior reversibility and long-life stability. [Display omitted] • 2D Mn 2 O 3 quantum dots embedded into N-doped carbon composites (MNC) was prepared. • Interfacial heterostructural C-O-Mn bonds boost Na storage stability and reversibility. • N doped carbon raises electronic conductivity and kinetic reaction rate. • MNC shows superior storage property for SIBs/SIHCs and practical applications. The ingenious architectural structural engineering is extensively identified as a cogent means for facilitating the electrochemical properties of conversion-type anode materials for sodium-ion storage. Herein, a delicate, scalable and controllable solvent-free strategy is proposed to synthesize ultrafine Mn 2 O 3 quantum dots embedded into N-doped carbon to generate two-dimensional (2D) composites (MNC) with robust interfacial heterostructural interactions for high sodium ion storage and fast reaction kinetics, which averts the use of solvents and environmental pollution, greatly reduces time and production costs. The introduction of metallic Mn species simultaneously achieves the construction of ultrafine Mn 2 O 3 quantum dots and strong interfacial heterostructural C O Mn bonds between metal species and 2D N-doped carbon matrix. The synergistic effect of the formation of oxide quantum dots, the combination of 2D N-doped carbon and the construction of robust interfacial interactions provides the stable electrode structure, fast reaction kinetics and high electrochemical storage capability of anode materials. Hence, MNC composites in SIBs convey remarkable reversible rate capability. Its superior capacity reaches 215 mAh g−1 for 50 cycles at 0.2 A g−1 and 155 mAh g−1 for 1000 cycles at a high current density of 5 A g−1, which shows good long-term stability. The assembled sodium-ion hybrid capacitors (SIHCs) device delivers outstanding energy density of 138 Wh kg−1 at a power density of 126 W kg−1 and 98% capacity retention after 2000 cycles at 2 A g−1, and tremendous capability for practical applications (69 LEDs can be easily lighted). This work not merely offers guidance for the rational interfacial engineering design of high-capacity Mn-based electrode materials in a feasible and scalable solvent-free tactics for Na+ storage, but also broadens the routes for projecting a better electrode material for other battery systems. [ABSTRACT FROM AUTHOR]

Abstract: Photoresponsive materials have tremendous potential applications in many fields. However, it is still a challenge to realize such materials, especially in isolated micro‐ or nanostructured form, with precisely controlled photomechanics for creating arbitrary deformations in a reversible way. Based on the coupling of photoinduced mass immigration with polymer networks, a general concept is proposed for producing nanostructured materials capable of reversibly creating arbitrary deformations. It is found for these type of materials the molecule alignment in the formation of a polymer network is not necessary to generate large anisotropic strain and stress. Importantly, the photoinduced mass immigration in a polymer network can provide unprecedented freedom in rapid exceptional spatiotemporal control over the molecule alignment profile and thus mechanical response within the network, enabling polymer formation of arbitrary deformations. Moreover, the inscribed molecule alignment profile is erasable and the fabricated materials can serve as a reconfigurable platform to present different mechanical behaviors. [ABSTRACT FROM AUTHOR]

To enhance the detection performance of hydrogen (H 2), we employed a self-sacrificing template method to prepare a three-dimensional (3D) PdCu-modified Ti 3 C 2 T x nanocomposite, denoted as PdCu/Ti 3 C 2 T x. Within 3D PdCu/Ti 3 C 2 T x nanocomposite, PdCu as the active center component, was evenly distributed on Ti 3 C 2 T x nanosheets. The unique architecture increased the exposure of active center sites, while the Ti 3 C 2 T x nanosheets provided additional gas diffusion channels, thereby contributing to improved gas sensing performance. Comparing to PdCu nanoparticles, PdCu/Ti 3 C 2 T x exhibited an enhancing response and a fast response time of 4 s to 0.5 % H 2. PdCu/Ti 3 C 2 T x also showed an ultra-low detection limit of 0.1 % H 2 and excellent repeatability, selectivity and long-term stability. The outstanding gas sensing performance could be attributed to the 3D structure and the heterostructure between PdCu and Ti 3 C 2 T x. The insights gained from this study provide novel perspectives for designing and synthesizing high-performance gas-sensitive materials. • Three-dimensional PdCu-modified Ti 3 C 2 T x nanocomposites were prepared by self-sacrificing template method. • The PdCu/Ti 3 C 2 T x nanocomposite has excellent sensing characteristics for hydrogen, and the response speed is only 4 s. • The outstanding sensing performance were attributed to the 3D structure and the heterostructure between PdCu and Ti 3 C 2 T x. [ABSTRACT FROM AUTHOR]

Graphical abstract The β-NiMoO 4 nanomrods were successfully fabricated by a green solid-state chemical approach and exhibit high electrochemical performance for supercapacitors. Abstract Simple solid-state chemical reaction was adopted to synthesize NiMoO 4 nanomaterials with different crystal phase without the use of organic solvent or templating agent. The as-prepared NiMoO 4 ·xH 2 O, α-NiMoO 4 and β-NiMoO 4 nanostructures were investigated as the electrode materials for supercapacitors. The β-NiMoO 4 nanorods were composed of the nanoparticles, which exhibited relatively high specific capacitances about 1415 F g−1 at a charge density of 1 A g−1, 80.2% of the initial reversible capacity was maintained after 1000 cycles. The β-NiMoO 4 //rGO asymmetric supercapacitor (ASC) system was assembled in serials, which displayed high specific energy density of 29.3 Wh kg−1 at a high power density of 187 W kg−1. This ASC system can drive the light-emitting diode (LED) effectively and give out light about 40 min, even easily light two LEDs in serials for 20 min. The remarkable electrochemical performances make the as-prepared NiMoO 4 nanostructures an excellent candidate as electrode materials for advanced supercapacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrafine Cu nanoparticles-encapsulated N-doped carbon nanosheets (Cu/NC) have been fabricated. • Cu/NC exhibits superior storage performance of lithium/sodium-ion batteries. • DFT indicates that the incorporating of Cu and N species in carbon enhanced Na+ adsorption ability. • SIHCs exhibit high energy/power density with ultra-long lifespan and practical applications. Carbon-based materials are extensively applied in Li/Na-ion batteries (LIBs/SIBs) anode material. Nevertheless, the poor rate performance, sluggish reaction kinetics, and fast capacity fading during cycling process seriously impedes large-scale commercial application. Herein, ultrafine Cu nanoparticles encapsulated within N-doped carbon nanosheets (labeled Cu/NC) with enlarged interlayer distances, increased intrinsic defects, abundant metallic Cu sites, and hierarchical porous structure were facilely and efficiently fabricated by a room-temperature grinding followed by high temperature pyrolysis. The Cu/NC as electrodes show a high capacity of 788 mAh g−1 in LIBs, and 434 mA h g−1 in SIBs at 0.2 A g−1, as well as good cycling stability with 123 mAh g−1 for LIBs and 177 mAh g−1 for SIBs at 10 A g−1 after 2000 cycles. The as-assembled sodium-ion hybrid capacitors (SIHCs) deliver a high energy/power density of 97 Wh kg−1 at 181 W kg−1, remarkable capacity retention of 95.8% after 10,000 cycles and practical applications (69 LEDs can be easily lighted). The experimental results couple with theoretical calculation indicate that the incorporating of Cu and N species can provide abundant active sites and structural defects, resulting in fast reaction kinetics for Li/Na-ion storage. [ABSTRACT FROM AUTHOR]