Graphene-supported anatase TiO2 nanosheets for fast lithium storage

We have designed a unique hybrid structure by directly growing ultrathin anatase TiO(2) nanosheets onto graphene support for fast lithium storage. With exposed (001) high-energy facets, these TiO(2) nanosheets serve as ideal hosts for fast and efficient lithium storage. On the other hand, the graphene support serves as a highly conductive substrate that is beneficial to the high-rate performance.     

Ultrathin two-dimensional metal-organic framework nanosheets for efficient electrochemical CO2 reduction

Electrochemical CO2 reduction into CO or high-value products is regarded as a feasible pathway for energy conversion, which has attracted universal attention in...     

Nanocomposites induced by two-dimensional titanium carbide nanosheets for highly efficient energy storage

Surface group-rich titanium carbide nanosheets (TCNSs) were successfully fabricated by simply etching Ti₃AlC₂ powders and used as dielectric fillers to promote the dielectric and energy storage performances of poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)-based composites. The PVDF-HFP/TCNS composites realize a high dielectric constant and low dielectric loss of 16.3 and 0.034 at 10² Hz, respectively. Importantly, a high energy storage density (U_e) of 0.367 J cm⁻³ at 900 kV cm⁻¹ and a high energy storage efficiency (η ≥ 78.9%) at a TCNS content of only 0.5 wt% are obtained, which indicates that incorporating TCNS is an efficient route in enhancing U_e while maintaining a high level η of the PVDF-HFP-based composites. According to detailed characterization results, a mechanism related to the reduction of lamellar crystals in the PVDF-HFP matrix is suggested. The above mechanism restricts the movement of polymer chains near the filler-matrix interface and is proposed to be responsible for the outstanding dielectric and energy storage performances. Consequently, this work provides a simple and effective method for fabricating highly efficient energy storage nanocomposites.     

垂直自支撑式金属有机框架多级结构单晶用于锂定向沉积

金属有机框架材料(MOF)是由金属离子或簇和有机配体通过配位键自组装形成的多孔晶体材料.MOF及其衍生物具有开放金属位点和极大的比表面积,广泛地应用在催化领域.然而,MOF材料由于存在暴露活性位点较少,传质受限或易发生不可控制的聚集等问题,会导致活性位点的损失,极大地限制了其在催化领域的应用.多级结构不仅提供更多的暴露...     

Thermal expansion-quench of nickel metal-organic framework into nanosheets for efficient visible light CO2 reduction

Metal-organic framework nanosheets (MOF NNs) offer potential opportunities for many applications,but an efficient strategy for the scalable preparation of few-layered two-dimensional (2D) MOF NNs are still a major challenge.Herein,we present an efficient top-down method for the synthesis of the Ni-BDC(Ni₂(OH)₂(1,4-BDC);1,4-BDC=1,4-benzenedicarboxylate) nanosheets utilizing a novel thermal expansionquench method of the flowerlike bulky MOFs in liquid N₂.The obtain...     

Superior lithium storage performance in MoO3 by synergistic effects:Oxygen vacancies and nanostructures

Molybdenum trioxide(MoO₃) has recently attracted wide attention as a typical conversion-type anode of Li-ion batteries(LIBs).Nevertheless,the inferior intrinsic conductivity and rapid capacity fading during charge/discharge process seriously limit large-scale commercial application of MoO₃.Herein,the density function theory(DFT) calculations show that electron-proton co-doping preferentially bonds symmetric oxygen to form unstable H_xMoO₃.When the-OH-gr...     

A unique hierarchical composite with auricular-like MoS2 nanosheets erected on graphene for enhanced lithium storage

Journal of Solid State Electrochemistry - Molybdenum disulfide (MoS2) is a promising anode material in lithium-ion batteries (LIBs) due to its high specific capacity and typical two-dimensional...     

2D DUT-8(Ni)-derived Ni@C nanosheets for efficient hydrogen evolution

Journal of Solid State Electrochemistry - The development of high-performance, low-cost, and high-stability catalysts for electrocatalytic hydrogen evolution reaction is a key step in the green and...     

Heterostructured MoS2/GPC anode: the synergistic lithium storage performance and lithiation kinetics

Journal of Solid State Electrochemistry - Grapefruit peel carbon (GPC) is prepared from waste grapefruit peel and further used as substrate for in situ construction of MoS2 arrays, forming MoS2/GPC...     

3D porous V_2O_5 architectures for high-rate lithium storage

The discovery of novel electrode materials promises to unleash a number of technological advances in lithium-ion batteries. V_2O_5 is recognized as a high-performance cathode that capitalizes on the rich redox chemistry of vanadium to store lithium. To unlock the full potential of V_2O_5, nanotechnology solution and rational electrode design are used to imbue V_2O_5 with high energy and power density by addressing some of their intrinsic disadvantages in macroscopic crystal form. Here, we demonstrate a facile and environmental-friendly method to prepare nanorods-constructed 3D porous V_2O_5 architectures(3 D-V_2O_5)in large-scale. The 3D porous architecture is found to be responsible for the enhanced charge transfer kinetics and Li-ion diffusion rate of the 3D-V_2O_5 electrode. As the result, the 3D-V_2O_5 surpasses the conventional bulk V_2O_5 by showing enhanced discharge capacity and rate capability(delivering 154 and127 m Ah g~(-1) at 15 and 20 C, respectively).     

TiO2 and SnO2@TiO2 hollow spheres assembled from anatase TiO2 nanosheets with enhanced lithium storage properties

TiO(2) and SnO(2)@TiO(2) hollow spheres assembled from anatase TiO(2) nanosheets with exposed (001) high-energy facets are constructed via a templating approach, and the as-prepared samples exhibit enhanced lithium storage properties.     

Trimetallic synergistic optimization of 0D NiCoFe-P QDs anchoring on 2D porous carbon for efficient electrocatalysis and high-energy supercapacitor

Developing multi-functional and low-cost noble-metal-free catalysts such as transition metal phosphides(TMPs) to replace noble-metal is of practical significance for energy conversion and storage. However, the low-durability and the agglomeration phenomenon during the electrochemical process limit their practical applications. Herein, using metal–organic frameworks(MOFs) as the precursor and a combined strategy of gradient temperature calcination and thermal phosphorization, a 0D/2D heterostruct...     

Zinc hydroxide nitrate nanosheets conversion into hierarchical zeolitic imidazolate frameworks nanocomposite and their application for CO2 sorption

Hierarchical porous zeolitic imidazolate frameworks (HZIFs) are promising materials for several applications, including adsorption, separation, and nanomedicine. Herein, the conversion of zinc hydroxide nitrate nanosheets into HZIF-8 nanocomposite with graphene oxide (GO) and magnetic nanoparticles (MNPs) is reported. The conversion takes place at room temperature in water. This approach has been successfully applied for the formation of leaf-like ZIF(ZIF-L), and their nanocomposites with nanoparticles, such as GO and MNPs. This method offers a simple approach for the synthesis of tunable pore structure using nanoparticles and fast room temperature conversion (30 min) without any visible residual impurities of zinc hydroxide nitrates. The applications of HZIF-8, ZIF-L, and their nanocomposites, for CO₂ sorption, exhibit excellent adsorption properties. The synthesized composites exhibit enhanced CO₂ adsorption capacity due to the synergistic effect between nanoparticles (GO, or MNPs), and ZIF-8. The materials have good potential for further applications.     

Hydrogen and halogen bonding drive the orthogonal self-assembly of an organic framework possessing 2D channels

Orthogonal self-assembly of an open organic framework showing 2D channels has been obtained by combining hydrogen and halogen bonding. The framework is able to host various guest molecules with a diverse set of steric demands and substitution patterns, and survives single-crystal-to-single-crystal guest exchanges from liquid and gas phases.     

Synthesis and storage performance of rGO-modified LiFePO4 nanosheets with exposed (010) facet for lithium ion batteries

Journal of Solid State Electrochemistry - LiFePO4 is considered one of the most attractive cathodes for Li ion batteries. However, the electrochemical properties of LiFePO4 are seriously restrained...     

Electrochemically exfoliated Ni-doped MoS2 nanosheets for highly efficient hydrogen evolution and Zn-H2O battery

Thanks to tunable physical and chemical properties, two-dimensional (2D) materials have received intensive interest, endowing their excellent electrocatalytic performances for applications in energy conversion. However, their catalytic activities are largely determined by poor adsorption energy and limited active edge sites. Herein, a one-step electrochemical exfoliation strategy was developed to fabricate 2D Ni-doped MoS₂ nanosheets (Ni-EX-MoS₂) with a lateral size of ～500 nm and thickness of ～3.5 nm. Profiting from high electrical conductivity and abundant exposing active sites, Ni-EX-MoS₂ catalyst displayed an admirable performance for electrochemical hydrogen evolution reaction (HER) with a low overpotential of 145 mV at 10 mA/cm² as well as a small Tafel slope of 89 mV/dec in alkaline media, which are superior to those of the most reported MoS₂-based electrocatalysts. The formed Ni species with tuning electronic structure played a crucial role as primary active center of Ni-EX-MoS₂, as well as the forming stable 1T/2H phase MoS₂ interface demonstrated a synergistic effect on electrocatalytic HER performance. Further, Ni-EX-MoS₂ was employed as a cathode electrode for alkaline Zn-H₂O battery, which displayed a high power density of 3.3 mW/cm² with excellent stability. This work will provide a simple and effective guideline for design of electrochemically exfoliated transition metal-doped MoS₂ nanosheets to inspire their practical applications in energy catalytic and storage.     

Boudouard reaction driven by thermal plasma for efficient CO2 conversion and energy storage

Conversion of CO2 into CO using plasma processing powered by renewable energy is a promising method to convert intermittent sustainable electricity into storable chemical energy.Despite extensive research efforts worldwide,there is currently no process that achieves economically viable values for both CO2 conversion fraction and energy recovery efficiency simultaneously.Here we demonstrate that a process that utilizes the Boudouard reaction,CO^2++C→2 CO,driven by a thermal plasma allows both 95%CO2 conversion to CO and energy recovery efficiency of 70%,values far higher than seen so far.By comparing the conversion process with and without CO2 excitation by a plasma and by using optical emission spectroscopy we show that the improved performance is due to a novel mode of operation where CO2 is pyrolyzed into an active mixture of CO,O and O2 by an arc discharge which is then introduced into a fixed bed to interact with carbon material.In this way,the free oxygen in the mixture combusts with carbon to form CO,and residual plasma excited CO2 is reduced by carbon.In the overall process,the endothermic Boudouard reaction is partially replaced by an exothermic reaction,and the excess electric energy to produce CO2 plasma is reused in the carbon bed.     

Emerging CoMn-LDH@MnO2 electrode materials assembled using nanosheets for flexible and foldable energy storage devices

CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.     

Multichannel hollow TiO2 nanofibers fabricated by single-nozzle electrospinning and their application for fast lithium storage

Multichannel hollow TiO₂ nanofibers were synthesized via a facile single-nozzle electrospinning method based on phase-separation mechanism. Compared to normal TiO₂ nanofibers, hollow TiO₂ with higher surface area gave rises to a higher surface contribution and ensured a short diffusion path for ion transport. Thus hollow TiO₂ demonstrated superior cyclic ability and excellent rate capability.