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Solid-state electrolyte (SSE) is promising for application in all-solid-state lithium metal batteries because of its reliable safety and longevity. The failure of SSE to suppress dendrite formation...

Lithium metal has been regarded as the most promising anode for the next generation high energy- density batteries. However, detrimental side reactions with electrolyte, uncontrollable lithium dendrite growth, distinct volume expansion and fragile solid electrolyte interface (SEI) layer lead to low coulombic efficiency (CE), rapid battery failure and even safety hazards, which hinders its practical application. Herein, we propose a novel composite anode which embeds Li metal particles into a Li+/electron hybrid conductive framework and is reinforced by CNTs. Sulfurized pyrolyzed poly(acrylonitrile) (S@pPAN), which is extensively studied as superior cathode materials, is creatively adopted to render abundant Li3N and Li2S on the surface of the Li particles and in the free-space. The in-situ formed hybrid framework not only provides a rapid Li+ transfer channel throughout the electrode, but also suppresses the Li dendrite growth and inhibits the volume expansion. With further assistance of lithiophilic nano-MgO, the composite anode achieved dense and reversible Li plating/striping. As a result, a long cycle life of more than 800 hours with 10 mAh cm−2 and excellent electrode kinetics are obtained for symmetric cells. Moreover, the full cells coupled with S@pPAN and LiFePO4 cathodes deliver a long and stable cycle life. The rational 3D composite anode design provides a feasible strategy to build high performance Li metal batteries.

In spite of the advances in understanding how to prepare concave Pd nanocubes, the quantitative measurement on how the salt precursor reduction process impacts the product is still concealed. Herei...

Li metal anode has been considered as the ideal anode for next-generation batteries due to its ultrahigh capacity and lowest electrochemical potential. However, its practical application is still impeded by low Coulombic efficiency, huge volume change, and safety hazards arising from Li dendrite growth. In this work, a three-dimensional (3D) structured highly stable Li metal anode is designed and easily preapred. Benefiting from the in situ reaction between Li metal and AlN, highly Li+ conductive Li3N and lithiophilic LiAl alloy have been simultaneously formed and homogeneously distributed in the framework, in which Li metal is finely dispersed and embedded. The outstanding electron/ion mixed conductivity of Li3N/LiAl and 3D composite structure with enhanced interfacial area significantly improve the electrode kinetics and suppress the volume change on cycling, while a lithiophilic effect of LiAl alloy and uniform distribution of Li ion flux inside the electrode avoid dendritic Li deposition. As a result, the proposed Li metal electrode exhibits exceptional electrochemical reversibility in both carbonate and ether-based electrolytes. Paired with LiFePO4 and sulfurized polyacrylonitrile (S@pPAN) cathodes, the full cells deliver highly stable and long-term cycling performance. Therefore, the proposed strategy to fabricate Li metal anodes could promote the practical application of Li metal batteries.

Although β-Fe2O3 has a high theoretical solar-to-hydrogen efficiency because of its narrow band gap, the study of β-Fe2O3 photoanodes for water splitting is elusive as a result of their metastable nature. Raman identification of β-Fe2O3 is theoretically and experimentally investigated in this study for the first time, thus clarifying the debate about its Raman spectrum in the literature. Phase transformation of β-Fe2O3 to α-Fe2O3 was found to potentially take place under laser and electron irradiation as well as annealing. Herein, phase transformation of β-Fe2O3 to α-Fe2O3 was inhibited by introduction of Zr doping, and β-Fe2O3 was found to withstand a higher annealing temperature without any phase transformation. The solar water splitting photocurrent of the Zr-doped β-Fe2O3 photoanode was increased by 500% compared to that of the pure β-Fe2O3 photoanode. Additionally, Zr-doped β-Fe2O3 exhibited very good stability during the process of solar water splitting. These results indicate that by improving its thermal stability, metastable β-Fe2O3 film is a promising photoanode for solar water splitting., The use of element doping to prevent the phase transition of metastable semiconductors has been approved for the application of photoelectrochemcial hydrogen production via water splitting for the first time.

To deal with the demulsification of O/W emulsions, a novel kind of core–shell structural amphiphilic soft matter, HPEI-g-Cn (n = 10, 12, 14, 16, 18), with hyperbranched polyethyleneimine (HPEI) as the core and fatty acid chain Cn as the shell, is designed and synthesized. With the existence of amphiphilic HPEI-g-Cn, O/W emulsions can be thoroughly separated into two phases with a clear oil–water interface to reach demulsification equilibrium within 40 min. The oil removal ratio can exceed 99.9% under the addition of 40 ppm in simulative emulsions, and simultaneously the water content in the oil phase is less than 0.01%. This demulsifier can also contribute to excellent separation efficiency (up to 99.9%) for O/W emulsions from two China's oilfields, and even for heavy oil emulsions. More importantly, it is noted that the HPEI-g-Cn demulsifiers after demulsification are evenly and tightly dispersed at the oil–water interface as shown by wide-angle X-ray scattering (WAXS) and cryo-electron microscopy (cryo-EM), which is beneficial to the subsequent recovery and utilization. With eco-friendly characteristics, outstanding demulsification performance and promising recyclability, the amphiphilic macromolecules HPEI-g-Cn as special soft matter display great promise to achieve industrial applications in the future.

Lithium metal is a promising candidate anode for next generation high energy density batteries. However, the Li dendrite growth results in electrode degradation and safety hazards, obstructing its ...

Using Li metal-free anodes for lithium-ion oxygen and lithium-ion sulfur batteries is considered as a promising solution to resolve the hazard of Li metal anode. Although Si anode exhibits high capacity and low electrochemical potential, it cannot match with oxygen (or sulfur) cathode, because both lack cycleable lithium ions. In this work, a free-standing and fibrous Si/C anode is prepared by electrospinning and its simple but effective lithiation is proposed. When assembling the cells, the free-standing Si/C anode was put between mass-controlled lithium metal foil and separator, and then the Si/C anode could be lithiated after adding electrolytes. By optimizing a LiFSI based ether electrolyte, the Si/C anode could achieve good cycleablity comparable to that in carbonate electrolytes. The lithiated Si–O2 cells exhibit better cycling stability than the lithium oxygen cells with gel polymer electrolye. Moreover, because both Si anode and S@pPAN cathode are compatible with carbonate electrolytes, exceptional cycling performance has been achieved for the lithiated Si–S cells. This simple method could pave the way to commercial applications of lithium-ion oxygen and lithium-ion sulfur batteries.

Charge transport in a photoelectrode largely influences its solar-to-chemical energy conversion efficiency. Especially, particle-assembled photoanode films are always subject to poor interparticle ...

The functions of heterogeneous metallic nanocrystals (HMNCs) can be undoubtedly tuned by controlling their morphologies and compositions. As a less-studied kind of HMNCs, corner-satellite multi-metallic nanocrystals (CSMNCs) have great research value in structure-related electrocatalytic performance. In this work, PdAgPt corner-satellite nanocrystals with well-controlled morphologies and compositions have been developed by temperature regulation of a seed-mediated growth process. Through the seed-mediated growth, the morphology of PdAgPt products evolves from Pd@Ag cubes to PdAgPt corner-satellite cubes, and eventually to truncated hollow octahedra, as a result of the expansion of {111} facets in AgPt satellites. The growth of AgPt satellites exclusively on the corners of central cubes is realized with the joint help of Ag shell and moderate bromide, and hollow structures form only at higher reaction temperatures on account of galvanic displacement promoted by the Pd core. In view of the different performances of Pd and Pt toward formic acid oxidation (FAO), this structure-sensitive reaction is chosen to measure electrocatalytic properties of PdAgPt HMNCs. It is proven that PdAgPt CSMNCs display greatly improved activity toward FAO in direct oxidation pathway. In addition, with the help of AgPt heterogeneous shells, all PdAgPt HMNCs exhibit better durability than Pd cubes and commercial Pt.

Metal nitrides are widely studied due to their outstanding physical properties, including high hardness, high thermal and chemical stability, low electrical resistivity etc. Generally, metal nitrides can be obtained from the direct reaction of metal and ammonia/nitrogen. However, some of the metal nitrides, such as Ta3N5, cannot be synthesized by direct nitridation of metals. To achieve Ta3N5, high-oxidation-state Ta precursors like Ta2O5, NaTaO3, TaS3, K6Ta10.8O30, Ta(N(CH3)2)5 and TaCl5 have to be employed, which is a time-consuming and laborious process with the possibility of introducing undesirable impurities. Here taking Ta3N5 as an example, a facile carbonate-assisted one-step nitridation method is proposed, which enables the direct synthesis of high-oxidation-state metal nitride films from metal precursors under ammonia flow. The mechanism of the nitridation process has been studied, which carbon dioxide released from carbonates decomposition reacts with metallic Ta and assists the one-step conversion of metallic Ta to Ta3N5. The as-prepared Ta3N5 film, after modified with NiFe layered double hydroxide, exhibits promising water splitting performance and stability. This method avoids the preoxidation process of metal precursors in high-oxidation-state metal nitride synthesis, and may facilitate the direct fabrication of other important metal nitrides besides Ta3N5.

A symmetrical, almost linear and planar motif 2,6-bis(1-phenyl-1,2,3-triazol-4-yl)-4-nitroaniline have been designed and synthesized by click chemistry. The synthesis of this novel structure is straightforward and inexpensive. Two kinds of polymorphic crystals are obtained in different solvents, suggesting the versatile intra- and intermolecular interactions. Theoretical calculation was used to study the linear absorption spectrum, which show good agreement with the experimental results. Linear optical property shows an absorption band centered at 368 nm. Nonlinear optical property displays a two-photon absorption cross sections around 200 GM under different power intensities. Therefore, this novel click-derived chromophore exhibits highly-transparent and stable two-photon absorption property.

In this study, we have successfully prepared in-situ synthesis of sulfur-doped graphene quantum dots decorated carbon nanoparticles (S-GQDs/CNPs) hybrid from low-cost fructose and H2SO4 by the hydrothermal method. Fructose molecules are dehydrated by concentrated sulfuric acid, then formed honeycomb carbon matrix including sulfate radical in the hydrothermal process, while H2SO4 catalyses the reaction and offers sulfur atom for the carbon material. The result of transmission electron microscopy (TEM) demonstrates that a lot of in-situ grown S-GQDs are decorated on carbon nanoparticles by π–π stacking in the hydrothermal process, advantages of both GQDs and carbon nanoparticles combined, which facilitates the electron transfer between S-GQDs and carbon nanoparticles. X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared (FT-IR) spectra show the presence of –C–S–C– bonds and the absence of oxygen-containing groups in S-GQDs/CNPs hybrid. As expected, the electrochemical data of S-GQDs/CNPs hybrid indicate that the layer by layer modified method can inhibit the occurrence of a two-electron pathway and cause a four-electron pathway for ORR. Moreover, the resulting S-GQDs/CNPs hybrid has a better methanol tolerance and long-term durability than commercial 20% Pt/C.

We report a new carbonate electrolyte of 1 M LiFSI dissolved in the EMC/FEC (70/30, v/v) solvent for lithium metal based batteries. Favorable LiF-rich SEI layer is formed on Li anode to suppress side reactions under the synergistic effect of LiFSI and FEC. Thus, the dendrite-free Li morphology and high Coulombic efficiency for Li plating/stripping can be obtained with improved cycle stability compared with conventional LiPF6/EC-DMC electrolyte. Li | S@pPAN cell assembled with the new electrolyte shows quite low lithium ion transfer resistance, excellent long cycle stability and rate performance. A high discharge capacity of 1270 mAh g−1 remains after 1000 cycles at 2 C, with an inappreciable capacity decay of 0.0015% per cycle. Due to the low interface impedance and high Li+ diffusion coefficient, a capacity of 1210 mAh g−1 even at 10 C can be maintained. This deliberately designed electrolyte offers new insights into the understanding of interfacial stability between electrolyte and Li anode. Furthermore, our work offers a new approach towards high energy-density and high rate Li-S battery.

CuW1− x Mo x O4 solid solution of CuWO4 and CuMoO4, which is a copper-based multi-component oxide semiconductor, possesses much narrower band gap than CuWO4. In theory, it can absorb a larger part of the visible spectrum, widening the use of solar spectroscopy and obtaining a higher photo-to-chemical conversion efficiency. In this study, CuW1− x Mo x O4 thin-film photoanodes on conducting glass were prepared using a simple and low-cost spray pyrolysis method. The resulting CuW1− x Mo x O4 photoanodes perform higher photocurrent than CuWO4 photoanodes under AM 1.5G simulated sunlight illumination (100 mW cm−2) in 0.1 mol L−1 phosphate buffer at pH 7. Combined with IPCE and Mott-Schottky analysis, the enhancement of the photocurrent is due to the improvement of photon utilization and the increase of carrier concentration with the incorporation of Mo atoms. Moreover, with the optimal Mo/W atomic ratio, the photocurrent density increases obviously from 0.07 to 0.46 mA cm−2 at 1.23 VRHE bias. In addition, compared with particle-assembled thin-film photoanodes prepared by solid-phase reaction and drop-necking treatment, the photoanodes prepared by spray pyrolysis have obvious advantages in terms of reducing resistance and facilitating charge transport.

In this work, small sulfur molecules (S2-4) confined in microporous graphitic carbon (MGC) demonstrates excellent performance in Li-S battery with carbonate-based electrolyte. The MGC is synthesized via the simultaneous activation and graphitization of peanut shell char promoted by K2FeO4, which possesses ultra-micropore (pore width

A new electrolyte composed of 4 M LiFSI in dibutyl ether (DBE) is proposed for Li-S batteries. Dissolution of lithium polysulfides is definitely inhibited by DBE. More impressively, the electrolyte ensures a high Coulombic efficiency for Li deposition/stripping (∼99.2%) without dendrite growth. Enhanced cycling stability is demonstrated when coupled with a sulfurized poly(acrylonitrile) (S@pPAN) cathode. This electrolyte offers new insight into electrolyte design for high performance Li-S batteries.

Although the lithium–sulfur battery exhibits high capacity and energy density, the cycling performance is severely retarded by dendrite formation and side-reactions of the lithium metal anode and the shuttle effect of polysulfides. Therefore, exploring lithium rich-alloy (or compound) anodes and suppressing the shuttling of polysulfides have become practical technical challenges for the commercialization of lithium–sulfur batteries. Here, a lithium ion sulfur full battery system combining a lithium-rich Li–Si alloy anode and sulfurized polyacrylonitrile (S@pPAN) cathode has been proposed. The free-standing CNF matrix supported Li–Si alloy anode is prepared by a simple and effective method, which is practical for scale-up production. The obtained Li–Si alloy anode demonstrates high cycling stability without dendrite growth, while the use of the S@pPAN cathode avoids the shuttle effect in carbonate electrolytes. The constructed Li–Si/S@pPAN battery could be cycled more than 1000 times at 1C and 3000 times at 3C, with a capacity fading rate of 0.01% and 0.03% per cycle. The exceptional performance should originate from the stable integrated anode structure and the excellent compatibility of the S@pPAN cathode and Li–Si alloy anode with carbonate electrolytes.

Active cooling of scramjets by endothermic hydrocarbon fuels is considered as an effective approach to addressing the thermal problem for hypersonic aircrafts. To accelerate the endothermic cracking reactions of these fuels for a better cooling capability, a strategy for hydrocarbon cracking using polymer-based macromolecular initiators has been proposed. To verify the universality of this strategy and also to enhance the solubility of macromolecular initiators, a novel polyester macromolecular initiator (MI) is designed. It is clarified that the MI features high-efficient thermal cracking of hydrocarbon fuels in a tubular reactor with an improved conversion ratio, gas yield, and alkene selectivity. The possible mechanism behind the macromolecular initiator is revealed on the basis of intermediate analyses and density functional theory (DFT) calculations, which show the radical fragments from MI decomposition are effective in accelerating JP-10 dehydrogenation. The successful implementation of polyester materials in hydrocarbon fuels holds immense promise for the optimal use of hydrocarbon fuels in hypersonic aircrafts.

Hyperbranched polyglycerol (HPG) is modified with dodecanethiol (DS) via the “thiol−ene” click reaction to obtain an amphiphilic product DSHPG. The molecular structures of DSHPG samples are characterized by NMR, FTIR, and GPC, and the thermal behaviors are characterized by DSC and TGA. Gold nanoparticles (Au NPs) are prepared with DSHPG as the stabilizer and surface-modification reagent. The size of Au NPs can be tuned by changing the molecular weight of HPG. It is observed that the HPG molecular weights of 1123, 3826, and 55,075 lead to the NP diameters of 4.1 nm for Au@DSHPG-1, 9.7 nm for Au@DSHPG-2, and 15.1 nm for Au@DSHPG-3, respectively. The morphology and size of Au NPs are characterized by TEM and DLS. Especially, the dispersion abilities of Au NPs in different pure solvents and co-solvent mixtures are investigated. The long alkyl chains on DSHPG give the ability of Au NPs to be well dispersed in nonpolar solvents. Hydrocarbon-based nanofluids can be obtained from the hydrophobic Au NPs dispersed into a series of hydrocarbons. The dispersion stability for Au NPs in hydrocarbons is monitored by UV-Vis spectroscopy, and the relative concentration of Au NPs is observed to still maintain over 80% after 3600 h.

One of the amidoamine-structured hyperbranched polymers is developed as an efficient macroinitiator to enhance the endothermic capacity of hydrocarbon fuels to meet the stringent cooling requirement of hypersonic aircrafts. Hyperbranched poly(amidoamine) (PAMAM) is treated with palmitoyl chloride to modify a lipophilic shell on the hydrophilic core, and the amphiphilic product, palmitoyl-hyperbranched poly(amidoamine) (PPAMAM), can be well-dissolved in hydrocarbon fuels. The long alkyl chains in PPAMAM break away from the core at about 200 °C, and the PAMAM core destructs around 400 °C. The high decomposition temperature of the core enables PPAMAM to be performed as a macroinitiator for hydrocarbon fuels. Thermal cracking of methylcyclohexane (MCH) from 600 to 720 °C with the addition of PPAMAM is carried out in an electrically heated tubular reactor under the pressure of 3.5 MPa. Significant improvements of the conversion, gas yield, and heat sink of MCH with PPAMAM are observed. The conversion of MCH is...

Although spinel zinc ferrite (ZnFe2O4), with a band gap of 1.9 eV, is a promising photoanode material for solar water splitting, its photoelectrochemical performance is usually hindered by poor charge carrier transport. Ti4+ doping was introduced to increase the charge carrier concentration and promote charge carrier transport in the ZnFe2O4 photoanode. Here, pure and Ti4+-doped ZnFe2O4 photoanodes were prepared by a fast and effective spray pyrolysis method. In the Ti-doped ZnFe2O4 photoanode, some of the Fe3+ sites in the crystal lattice are substituted by Ti4+, as shown by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometry (FTIR) analyses. The results of Mott–Schottky analysis and electrochemical impedance spectroscopy (EIS) indicated that the substitution of Fe3+ by Ti4+ enhances the charge carrier concentration and electron transfer efficiency. The Ti-doped ZnFe2O4 photoanodes exhibit a solar water-splitting photocurrent of 0.35 mA cm−2 at 1.23 V vs. RHE (reversible hydrogen electrode), which is 8.75 times higher than that of the pure ZnFe2O4 photoanodes. Hence, this study may provide a simple route to fabricate multi-metal oxide photoelectrodes through ion doping to enhance their photoelectrochemical performances.

The solid polymer electrolyte (SPE) has been regarded as a promising candidate for the next-generation rechargeable Li metal battery with high-energy density. However, the current SPEs are still challenged by insufficient security owing to their flammability. Here, we reported a novel inherently flame-retardant SPE (IFR-SPE), which was fabricated via the one-step in situ crosslinking of two novel synthetic P-containing monomers with porous polyimide film as a supporting host. Compared with liquid and conventional solid polyethylene oxide electrolytes, the unique IFR-SPE exhibits outstanding flame-retardant ability. Furthermore, it demonstrates a high Li-ion conductivity (0.28 mS cm−1 at 25 °C), a stable electrochemical window up to 4.12 V, and effective Li dendrite suppression via a LiF/Li3PO4-rich solid electrolyte interphase formed on the Li anode. Consequently, the Li/IFR-SPE/LiFePO4 cell shows acceptable electrochemical performances. We believe that this work offers a novel and effective strategy for establishing a promising Li metal battery system with high safety.

To break oil-in-water emulsions with an average oil droplet size of

Although shape and size controllable palladium nanocrystals have attracted enormous attention, the growth behavior of Pd nanocubes is not thoroughly understood. In this work, the growth pattern of size controllable Pd nanocubes is studied systematically under a variety of reaction conditions. During the growth process of the Pd nanocubes, various structures including concave cubes, triangular bipyramids, pentagonal bipyramids (decahedrons) and pentagonal rods can be generated due to the disparate behavior of the fresh Pd atoms. Different-sized nanocubes are prepared controllably by changing the dosage of KBr, which provides capping capacities toward the {100} facets that the cubes are enclosed with. Both ascorbic acid (AA) and KBr influence the reducing rate of the Pd precursors and the growth kinetics of the nanocrystals, and furthermore control the morphologies of the products. This detailed research supplements the understanding of crystal growth, and provides insight toward the comprehension of atom movements at the nanoscale.

Nanoparticle-assembled films of hexagonal YFeO3 with a wide-spectrum response were prepared by electrophoretic deposition. Hexagonal YFeO3, with the band gap of 1.88 eV, was found to exhibit photoelectrochemical water splitting.

Ethylcyclohexane is a representative component of endothermic hydrocarbon fuel. The present work involved a comprehensive investigation of the pyrolysis process of ethylcyclohexane at different temperatures and times as well as its kinetics. At the test temperature T ranges from 683 to 723 K, the pyrolysis process of ethylcyclohexane conformed to the first-order kinetics. The apparent rate constants at different test temperatures were obtained, along with the corresponding Arrhenius parameters of pre-exponential factor A = 1.14 × 1015 s−1 and apparent activation energy Ea = 270 kJ/mol. The kinetics parameters for the pyrolysis of ethylcyclohexane were compared with those of several typical hydrocarbon compounds, and the results showed that thermal stabilities at given temperatures were arranged with the following order: 1,3,5-triisopropylcyclohexane

One of hyperbranched polymers is developed as a novel nanoscale initiator to enhance the heat sink of endothermic hydrocarbon fuels to meet the great cooling requirement of hypersonic aircrafts. In this work, the hyperbranched polyglycerol (HPG) is treated with palmitoyl chloride to obtain a fuel-soluble product, palmitoyl-hyperbranched polyglycerol (PHPG). The thermogravimetric analyses show that the long-alkyl chains rupture first from the matrix at about 200 °C, and then the HPG core breaks around 400 °C during the cracking of PHPG, which indicates a high decomposition temperature for this “macroinitiator”. The cracking processes of n -tridecane with PHPG in different molecular weights and addition quantities are performed in an electrically heated tube reactor under supercritical conditions (3.5 MPa, and 600–720 °C). PHPG can promote the cracking of n -tridecane with significant improvements of the conversion and heat sink. The conversion of n -tridecane is improved as high as 17.6% at 690 °C, and the corresponding heat sink is improved from 3.0 MJ/kg to 3.5 MJ/kg. Furthermore, the optimum addition quantity and molecular weight range of PHPG are chosen for the practical application to an aviation kerosene under 600–700 °C, and the increases of heat sink in comparison with those from the thermal cracking confirm the potential application of PHPG to endothermic hydrocarbon fuels.

For a comprehensive understanding of the properties of 1,3-dimethyladamantane (1,3-DMA) as a candidate of high energy-density hydrocarbon fuels, thermal stability of 1,3-DMA under different conditions is investigated. The thermal decomposition kinetics in the batch reactor between 693 and 743 K has been determined, with the rate constants ranging from 4.00 × 10–7 s–1 at 693 K to 35.19 × 10–7 s–1 at 743 K, along with the Arrhenius parameters of A = 2.39 × 107 s–1 and activation energy Ea = 183 kJ·mol–1. The rate constants for the thermal decomposition of 1,3-DMA are observed to be smaller than those of some typical model fuels, decalin, propylcyclohexane, butylcylohexane, and n-dodecane, demonstrating that the thermal stability of 1,3-DMA is satisfactory. The thermal decomposition of 1,3-DMA in the flowing reactor at temperatures from 873 to 973 K and pressures from 0.1 to 5.0 MPa is further performed. It can be observed that the conversion of 1,3-DMA and the yield of gaseous products increase clearly with...

All halogen containing electrolytes for Mg battery are apt to corrode conventional metal current collectors. In this paper, a new type of halogen-free boron based electrolyte (Mg[Mes3BPh]2/THF) is designed and prepared. Electrochemical tests show that this electrolyte system possesses high ion conductivity (1.5 × 10−3 S cm−1) and good Mg deposition–dissolution reversibility. More importantly, the same electrochemical window (2.6 V vs. Mg RE) of the electrolyte on Pt and stainless steel electrodes indicates that halogen-free electrolyte indeed lessens the corrosion to conventional metal current collectors. The surface morphologies of stainless steel, aluminum and copper are further observed after their anodic potentiostatic polarization in 0.25 mol L−1 Mg[Mes3BPh]2/THF electrolyte solution for 2 days. A comparison with halogen containing electrolytes proves that the presence of halogen in electrolyte is the reason for corrosion. This work provides a stepping stone for developing new halogen-free electrolyte systems for rechargeable Mg batteries.

Resorcinarene-encapsulated nickel nanoparticles with an average diameter of 35 nm have been successfully fabricated. Characterization results by particle size analyzer show that the obtained nanoparitcles can be well dispersed in the JP-10. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) indicate that resorcinarene are well capped on the nickel nanoparticles. A novel pseudohomogeneous method of catalytic decomposition of JP-10 is developed using these well-dispersed nickel nanoparticles. Compared with thermal decomposition, catalytic reaction of JP-10 on nickel nanoparticles exhibits remarkably enhanced conversion. The content of hydrogen and alkene of catalytic reaction is higher than that of thermal one from 540 to 600 °C.

For efficient thermal management in hypersonic aircraft, a series of highly stable macroinitiator/platinum/hydrocarbon nanofluids with great energy absorption capacity were designed in this work. Pt nanoparticles capped by hydrophobic hyperbranched polyglycerol (HMS) with average sizes of 1.2 nm and high dispersibility in hydrocarbons were synthesized through a facile phase transfer method and named as Pt@HMS. Nanofluids consisting of methylcyclohexane and Pt nanoparticles (MCH + Pt@HMS) presented admirable stability in the 180-day storage. On a simulated cooling channel of aircraft, the cracking performance and the energy absorption capacity of MCH + Pt@HMS were promoted significantly. At 650 °C, the heat sink of MCH + Pt@HMS reached 2.39 MJ/kg with an increase of 20.7% compared to thermal cracking. Larger macroinitiators HMS were beneficial. To acquire the same heat sink of 2.20 MJ/kg, the temperature can be lowered from 675 °C to 664 °C, 653 °C and 638 °C for the MCH + Pt@HMS with macroinitiator molecular weights of 3 k, 5 k and 13 k, respectively. The enhancements were ascribed to the synergistic catalysis of Pt@HMS. Endothermic reactions generating hydrogen and unsaturated hydrocarbons with higher enthalpies of formation were preferred for the cracking of MCH + Pt@HMS. Highly stable macroinitiator/platinum/hydrocarbon nanofluids are potential alternatives with great cracking performance and energy absorption capacity for efficient thermal management in hypersonic aircraft.

To accelerate the thermal cracking of hydrocarbon fuels and improve the cooling capacity for aircraft heat exchangers, cetyl-hyperbranched polyethyleneimine (CHPEI) synthesized from the modification of hyperbranched polyethyleneimine (HPEI) with a lipophilic alkyl chain was used as a novel macroinitiator. The pyrolysis performances under supercritical conditions (4.0 MPa, and 600–700 °C) of Jet propellant-10 (JP-10 or exo-tricyclo[5.2.1.02.6]decane) with CHPEI and the monomer triethylamine were compared in an electrically heated alloy tube. Both types of initiators with C-N bonds can promote the thermal cracking of JP-10, while CHPEI with a large molecular weight shows a similar crack-promoting effect to that of triethylamine with adding only one-tenth of the amount of the latter. As a typical example, the addition of 0.20 wt% CHPEI increased the conversion rate of JP-10 from 16.4% to 33.9%, and the corresponding heat sink was improved from 1.96 MJ/kg to 2.18 MJ/kg at 675 °C. On the basis of investigations on the intermediate species from different decomposition pathways of JP-10, it is proved that CHPEI accelerates the thermal cracking of JP-10 by generating lots of free radicals to participate in the H-abstraction reaction of JP-10. These efforts demonstrate that the macroinitiator CHPEI displays a great promise in hydrocarbon fuels for hypersonic applications.

Self-assembled silver nanoparticles with an average diameter of 5 nm have been successfully fabricated by reduction of Ag+ with ascorbic acid in the mixture of water, alkylamine, and oleic acid. Thermogravimetry (TG), differential scanning calorimetry (DSC), and contact angle measurements indicate that oleic acid molecules are well capped on the silver nanoparticles. The effects of temperature and reaction-medium pH on the morphology and composition of the silver nanoparticles are discussed. A decrease in pH leads to a tendency to produce silver nanorods and nanospheres. The temperature can affect the thickness of the organic layer on the surfaces of the silver nanoparticles. The stabilities of the silver nanoparticles in the nanofluids were monitored at different temperatures. Thermal conductivity enhancements were determined in kerosene-based nanofluids with the prepared silver nanoparticles. The surface-capped silver nanoparticles exhibited excellent dispersity in kerosene and conventional organic solv...

Many metal-oxide candidates for photoelectrochemical water splitting exhibit localized small polaron carrier conduction. Especially hematite (α-Fe2O3) photoanodes often suffer from low carrier mobility, which causes the serious bulk electron-hole recombination and greatly limits their PEC performances. In this study, the charge separation efficiency of hematite was enhanced greatly by coating an ultrathin p-type LaFeO3 overlayer. Compared to the hematite photoanodes, the solar water splitting photocurrent of the Fe2O3/LaFeO3 n–p junction exhibits a 90% increase at 1.23 V versus the reversible hydrogen electrode, due to enlarging the band bending and expanding the depletion layer.

Metal–semiconductor–metal-structured GaN ultraviolet photodetectors have been fabricated on sapphire substrates by metalorganic chemical vapor deposition. The properties of GaN photodetectors have been improved through thermal annealing. With a 3 V bias, the very low dark current is about 200 pA, the maximum responsivity of 0.19 A/W is achieved at 362 nm, and the corresponding detectivity is 1.2×1011 cm Hz1/2/W. The physical mechanism of the effects of thermal annealing also has been studied.