Nanoenergetic Composites with Fluoropolymers: Transition from Powders to Structures.

Over the years, nanoenergetic materials have attracted enormous research interest due to their overall better combustion characteristics compared to their micron-sized counterparts. Aluminum, boron, and their respective alloys are the most extensively studied nanoenergetic materials. The majority of the research work related to this topic is confined to the respective powders.

Reversible Al Metal Anodes Enabled by Amorphization for Aqueous Aluminum Batteries.

Aqueous aluminum metal batteries (AMBs) are regarded as one of the most sustainable energy storage systems among post-lithium-ion candidates, which is attributable to their highest theoretical volumetric capacity, inherent safe operation, and low cost. Yet, the development of aqueous AMBs is plagued by the incapable aluminum plating in an aqueous solution and severe parasitic reactions, which results in the limited discharge voltage, thus making the development of aqueous AMBs unsuccessful so far. Here, we demonstrate that amorphization is an effective strategy to tackle these critical issues of a metallic Al anode by shifting the reduction potential for Al deposition.

A Defect Engineered Electrocatalyst that Promotes High-Efficiency Urea Synthesis under Ambient Conditions.

Synthesizing urea from nitrate and carbon dioxide through an electrocatalysis approach under ambient conditions is extraordinarily sustainable. However, this approach still lacks electrocatalysts developed with high catalytic efficiencies, which is a key challenge. Here, we report the high-efficiency electrocatalytic synthesis of urea using indium oxyhydroxide with oxygen vacancy defects, which enables selective C-N coupling toward standout electrocatalytic urea synthesis activity.

Decomposition and Energy-Enhancement Mechanism of the Energetic Binder Glycidyl Azide Polymer at Explosive Detonation Temperatures.

Replacing existing inert binders with energetic ones in composite explosives is a novel way to improve the explosive performance, on the proviso that energetic binders are capable of releasing chemical energy rapidly in the detonation environment. Known to be a promising candidate, the reaction mechanism of glycidyl azide polymer (GAP) at typical detonation temperatures higher than 3000 K has been theoretically studied in this work at the atomistic level. By analyzing and tracking the cleavage of characteristic chemical bonds, it was found that at the detonation temperature, GAP was able to release a large amount of energy and small molecule products at a speed comparable to commonly used explosives in the early reaction stage, which was mainly attributed to the decomposition of azide groups into N and the main chain breakage into small fragments.

A novel environmental-friendly and safe unpacking powder without magnesium, aluminum and sulphur for fireworks.

A novel environmental-friendly unpacking powder for fireworks which has no sulfur, no magnesium, no aluminum or their alloys has been prepared in this study: potassium perchlorate (75%), potassium hydrogen terephthalate (13%), micronano porous silicon (9%), carbon (2%), ferrocene (1%). The PM2.5 and PM10 were collected by the ambient air particulate sampler, and the gas product was tested with a smoke analyzer and gas chromatograph to investigate its environmental-friendly performance.

Theoretical studies on the structures, material properties, and IR spectra of polymorphs of 3,4-bis(1H-5-tetrazolyl)furoxan.

Theoretical studies on the structures, densities, and heats of formation of conformational isomers of 3,4-bis(1H-5-tetrazolyl)furoxan (HBTF) were performed based on density functional theory (DFT) calculations. Two stable planar conformational isomers, the face-to-back and the back-to-face conformers, and one stable slightly twisted conformer, the back-to-back conformer, were predicted for HBTF at the M06-2X/6-311 + G(d,p) level of theory. The face-to-back conformer was calculated to be the most stable conformational isomer on the potential energy surface.

2D Black Phosphorus for Energy Storage and Thermoelectric Applications.

Recent progress in the currently available methods of producing black phosphorus bulk and phosphorene are presented. The effective passivation approaches toward improving the air stability of phosphorene are also discussed. Furthermore, the research efforts on the phosphorene and phosphorene-based materials for potential applications in lithium ion batteries, sodium ion batteries, and thermoelectric devices are summarized and highlighted.

General Approach for MOF-Derived Porous Spinel AFe2O4 Hollow Structures and Their Superior Lithium Storage Properties.

A general and simple approach for large-scale synthesis of porous hollow spinel AFe2O4 nanoarchitectures via metal organic framework self-sacrificial template strategy is proposed. By employing this method, we can successfully synthesize uniform NiFe2O4, ZnFe2O4, and CoFe2O4 hollow architectures that are hierarchically assembled by nanoparticles. When these hollow microcubes were tested as anode for lithium ion batteries, good rate capability and long-term cycling stability can be achieved.

Achieving Site-Specificity in Multistep Colloidal Synthesis.

We show that partial inhibition of the emerging Ag domain can be achieved by controlling the growth dynamics. With the symmetry broken by the "fresh" surface, sequentially growth gives (Au sphere)-(Ag wire)-(Ag plate) triblock nanostructures. This new understanding opens doors to sophisticated synthetic designs, broadening the horizon of our search for functional architectures.

Multifunctional Architectures Constructing of PANI Nanoneedle Arrays on MoS2 Thin Nanosheets for High-Energy Supercapacitors.

Multifunctional MoS2 @PANI (polyaniline) pseudo-supercapacitor electrodes consisting of MoS2 thin nanosheets and PANI nanoarrays are fabricated via a large-scale approach. The superior capacitance retention is retained up to 91% after 4000 cycles and a high energy density of 106 Wh kg(-1) is delivered at a power density of 106 kW kg(-1) .

Fabrication of flexible thermoelectric thin film devices by inkjet printing.

Ink-jet printing of thermoelectric nanomaterials is successfully used to fabricate flexible thin film TE devices for power generation and cooling.

Synthesis of two-dimensional transition-metal phosphates with highly ordered mesoporous structures for lithium-ion battery applications.

Materials with ordered mesoporous structures have shown great potential in a wide range of applications. In particular, the combination of mesoporosity, low dimensionality, and well-defined morphology in nanostructures may exhibit even more attractive features. However, the synthesis of such structures is still challenging in polar solvents.

Gas flow induced by ultrasonic cavitation bubble clouds and surface capillary wave.

In this paper, we report a gas flow phenomenon induced by ultrasonic water cavitation and capillary wave in a vibrating hollow tip and reflector system. The cavitation clouds generated a gas suction force and the capillary wave created tunnels through which the gas could go into the liquid. The gas flow rate was measured and compared under different conditions, including applied power, type of reflector, and tip-to-reflector distance.

Fe-based metallopolymer nanowall-based composites for Li-O2 battery cathode.

Metallopolymer nanowalls were prepared through a simple wet-chemical process using reduced graphene oxides as heterogeneous nucleation aids, which also help to form conductive electron paths. The nanowalls grow vertically on graphene surface with 100-200 nm in widths and ∼20 nm in thickness. The Fe-based metallopolymer nanowall-based electrode shows best performance as O2 cathode exhibiting high round-trip efficiencies and stable cycling performance among other transition metal containing metallopolymer counterparts.

n-Type carbon nanotubes/silver telluride nanohybrid buckypaper with a high-thermoelectric figure of merit.

n-Type thermoelectric (TE) materials was made from carbon nanotube (CNT) buckypapers. We used silver telluride (Ag2Te) to achieve electron injection to the CNTs. The TE characterizations on more than 50 samples show that the CNTs/Ag2Te hybrids exhibit negative Seebeck coefficients (e.

Aqueous-based chemical route toward ambient preparation of multicomponent core-shell nanotubes.

Room-temperature synthesized V2O5@MnO2 core-shell nanotubes with tunable tunnel dimensions via a facile aqueous-based method are presented. The rational-designed tubular morphology endows them with good permeability of electrolyte ions for maximum utilization of the electroactive sites, while the epitaxial-grown MnO2 imposes mechanical support to V2O5 against structural collapse upon long-term cycling. Hence, specific capacitance as high as 694 F g(-1) is achieved at 1 A g(-1) accompanied by excellent cycling stability (preserved 92% of its initial specific capacitance after 5000 cycles).

Ultrahigh rate capabilities of lithium-ion batteries from 3D ordered hierarchically porous electrodes with entrapped active nanoparticles configuration.

Three dimensional (3D) ordered hierarchically porous electrodes with an entrapped active nanoparticles configuration afford an extremely effective conductive 3D network from the micrometer to the nano meter scale for fast electron and Li-ion transport, and also allow the development of a stable solid electrolyte interphase over the electrode materials, therefore exhibiting extraordinary rate capabilities.

Bio-inspired antireflective hetero-nanojunctions with enhanced photoactivity.

A bio-inspired antireflective hetero-nanojunction structure has been fabricated by the hydrothermal growth of ZnO nanorods on silicon micro-pyramids. It has been shown that this structure suppresses light reflection more effectively resulting in a high photocurrent response and good charge separation simultaneously. The strategy provides a means to enhance solar energy conversion.

Binder-free graphene foams for O2 electrodes of Li-O2 batteries.

We report a novel method to prepare bind-free graphene foams as O2 electrodes for Li-O2 batteries. The graphene foams are synthesized by electrochemical leavening of the graphite papers, followed by annealing in inert gas to control the amount of structural defects in the graphene foams. It was found that the structural defects were detrimental to the processes of the ORR and OER in Li-O2 batteries.

Carbon inverse opal entrapped with electrode active nanoparticles as high-performance anode for lithium-ion batteries.

Enhancing ion and electron transport kinetics together with improving cycle life are important issues to be considered when developing high-performance Li ion batteries. Here we demonstrate a three dimensional ordered macroporous conductive electrode concept by entrapping electrode active nanoparticles in an interpenetrating macroporous carbon inverse opal. The electrodes are featured with simultaneously enhanced ion and electron transport kinetics as well as geometrically constrained active nanoparticles.

Olivine-type nanosheets for lithium ion battery cathodes.

Olivine-type LiMPO4 (M = Fe, Mn, Co, Ni) has become of great interest as cathodes for next-generation high-power lithium-ion batteries. Nevertheless, this family of compounds suffers from poor electronic conductivities and sluggish lithium diffusion in the [010] direction. Here, we develop a liquid-phase exfoliation approach combined with a solvothermal lithiation process in high-pressure high-temperature (HPHT) supercritical fluids for the fabrication of ultrathin LiMPO4 nanosheets (thickness: 3.

Cu doped V2O5 flowers as cathode material for high-performance lithium ion batteries.

Hierarchical Cu doped vanadium pentoxide (V2O5) flowers were prepared via a simple hydrothermal approach followed by an annealing process. The flower precursors are self-assembled with 1D nanobelts surrounding a central core. The morphological evolution is investigated and a plausible mechanism is proposed.

Facile preparation of ordered porous graphene-metal oxide@C binder-free electrodes with high Li storage performance.

A facile and general method is reported to prepare ordered porous graphene-based binder-free electrodes on a large scale. This preparation process allows the easy adjustment of the selected components, weight ratio of componets, and the thickness of the electrodes. Such ordered porous electrodes demonstrate superior Li storage properties; for example, graphene-Fe3 O4 @C depicts high capacities of 1123.