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Development of highly active and durable non-precious metal bi-functional electrocatalyst for both oxygen reduction and evolution reaction (ORR and OER) remains a significant challenge. Herein, porous mixed spinel MnCoxO4 was loaded on the N-doped multi-walled carbon nanotubes (MnCoxO4/NCNT) through a facile one-pot hydrothermal method to work as a bi-functional oxygen electrocatalyst. Physical characterizations confirm that the MnCoxO4 nanoparticles are composed of mixed spinel-type Co2MnO4 and (Co, Mn)[Mn, Co]2O4 with a diameter of 5–10 nm, which are dispersed on NCNT with secondary aggregation and resultant porous structure. Electrochemical measurements show that the MnCoxO4/NCNT catalyst exhibits high ORR catalytic activity with a dominant four-electron ORR catalytic pathway, remarkable durability, excellent methanol-tolerance, as well as superior OER catalytic activity with significantly decreased overpotential of 0.479 V in alkaline media. The multiple valence states of Co and Mn ions in MnCoxO4 coupled with the enlarged specific surface area with the help of NCNT exert crucial roles for the superior catalytic performance for both ORR and OER. Such a bi-functional oxygen electrocatalyst based on mixed spinel MnCoxO4 provides a new direction for developing low-cost, highly efficient, and robust multiple valence states transition metal-based electrocatalysts for oxygen electrode.

With the increasing attention to environmental pollution, the recycling and modification of wasted plastics has attracted more and more attention. In this study, zinc dimethacrylate (ZDMA) was first used to introduce ionic crosslinking into recycled acrylonitrile-butadiene-styrene (rABS)/recycled high-impact polystyrene (rHIPS) blends. On one hand, ZDMA underwent self-polymerization to form poly-ZDMA (PZDMA) particles. On the other hand, ionic crosslinks were formed by grafting with butadiene on the rABS or rHIPS chains of ZDMA. The ionic interaction between Zn2+ and unsaturated carboxylate was used to improve the compatibility between rABS and rHIPS. The enhanced impact strength, tensile strength, storage modulus and loss modulus of the blends were observed. In the case of 4 wt% ZDMA, the notched impact strength was 8.71 kJ/m2, 133% higher than that of blends without ZDMA. Scanning electron microscope (SEM) showed that polybutadiene (PB) had a good dispersion in rABS/rHIPS blends, the interface between rABS and rHIPS was indistinct, suggesting good compatibility. This indicated that the compatibility of rABS/rHIPS blends can be improved by using ion crosslinking.

Controllable growth of uniform nanoparticles with specific morphology to obtain high active electrocatalyst is a key common problem in developing efficient energy conversion and storage devices. In this work, a tangerine peel-derived carbon (TPC) supported mixed manganese oxides (MnOx/TPC) was synthesized for oxygen reduction reaction (ORR) through a facile pyrolysis procedure. By making full use of the confinement effect of tangerine peel cells, the MnOx nanoparticles of MnOx/TPC-800 are obtained with a components of Mn(II), Mn(III) and Mn(IV) with cubic morphology of about 15 nm and evenly dispersed on the TPC surface. Electrochemistry measurements show that MnOx/TPC-800 demonstrates excellent ORR performance with a comparable half-wave potential to commercial Pt/C and a high onset potential with a dominant 4e− catalytic process, superior stability, and remarkable immunity to methanol crossover effect in alkaline media. The synergy effect between multi-oxidation states MnOx and TPC of MnOx/TPC-800 is proved to play significant factor for its high ORR performance. This study provides a valuable and rational strategy to construct morphology-controlled metal nanoparticles with unique carbon materials in developing cost-effective catalysts for fuel cells and metal air batteries.

Exploring cost-effective, high-performance and durable non-precious metal catalysts is of great significance for the acceleration of sluggish oxygen reduction reaction (ORR). Here, we report an intriguing heteroatom-doped graphitized carbon encased Fe species composite by introducing N, S and B sequentially. The experimental approach was designed ingeniously for that the FeCl3·6H2O could catalyze thiourea to synthesize N, S co-doped carbon materials which would further react with H3BO3 and NH3 (emerged at the heat-treatment process) to prepare N, S and B co-doped carbon materials (Fe-N/S/B-C). The Fe-N/S/B-C exhibits an impressive ORR activity for its half-wave potential of −0.1 V, which is 36 mV or 19 mV higher than that of the corresponding single or dual doped counterparts (Fe-N-C or Fe-N/S-C) and 31 mV positive than that of Pt/C catalyst, respectively. Further chronoamperometric measurement and accelerated aging test confirm the excellent electrochemical durability of Fe-N/S/B-C with the stable core–shell structure. The remarkable ORR performance and facile preparation method enable Fe-N/S/B-C as a potential candidate in electrochemical energy devices.

Controlled synthesis of efficient core-shell non-precious metal catalysts for oxygen reduction reaction (ORR) is undoubtedly crucial but challenging for the extensive application of fuel cells and metal-air batteries. Herein, we prepared a core-shell structured Fe/FeCx nanoparticles and porous carbon composited catalyst (Fe/FeCx@NC) via a facile two-step heat treatment strategy. The Fe/FeCx@NC-800−0.5 prepared with secondary anneal at 800 °C for 0.5 h exhibits superior ORR performance to the commercial Pt/C in terms of comparable onset potential, higher half-wave potential, and outstanding long-term durability in alkaline media. Through combining the physical and electrochemical characterizations of Fe/FeCx@NC-T−t with different anneal temperature and precursors, the outstanding ORR performance of Fe/FeCx@NC-800−0.5 is caused by the synergistic effect between Fe/FeCx core and enriched pyridinic N- and graphitic N-doped carbon shell as well as porous carbon with large specific surface area. The structure-activity relationship of core-shell structured Fe–N–C catalysts for ORR provides directions for the development of advanced nonprecious metals catalysts.

Exploring low-cost and high-performance nonprecious metal catalysts for oxygen reduction reaction (ORR) in fuel cells is crucial for the commercialization of energy conversion and storage devices. Here we report a three-dimensional hierarchical porous Fe, N doped carbon catalysts synthesized by a facile pyrolysis method using silica nanospheres as template, glucose, FeSO 4 ·7H 2 O and dicyandiamide as the carbon, iron and nitrogen precursors, respectively. The corresponding 3DHP/Fe-N-C-900 catalyst exhibits superior ORR activity with the onset potential of 0 V ( vs . Ag/AgCl) and long-term stability than that of 20 wt. % Pt/C in alkaline medium. The excellent ORR performance of 3DHP/Fe-N-C-900 can be attributed to the synergistic effect of Fe 3 O 4 and doped N, as well as the three-dimensional meso/macroporous structure with high surface area. The finding of high ORR activity of Fe 3 O 4 nanoparticles coupling with hierarchical porous N-doped carbon materials opens a new avenue for the construction of cost-effective Fe-N-C catalysts for fuel cells.

Development of efficient, low-cost and good stability electrocatalysts as alternatives to platinum for the oxygen reduction reaction (ORR) is of significance for fuel cells. Here we report a novel type of Fe, N supported carbon nanotube encapsulated with nitrogen doped graphene as an ORR electrocatalyst synthesized by a hydrothermal method, for which nitrogen-enriched melamine, ferric chloride and disodium edentate were used as the nitrogen, iron and graphene precursors, respectively. Disodium edentate plays an important role in the performance towards the ORR because it is not only a graphene precursor, but also the key of forming FeNx active sites. The prepared Fe-N-CNT@GN catalyst exhibits high ORR activity in alkaline media with an onset potential of −0.13 V, a limiting current density of 6.2 mA cm−2, and higher selectivity (number of electron transfer n ∼ 3.8) which might be due to the FeNx active sites. Moreover, the half-wave potential exhibits almost no changes after 8000 continuous cycles scanning from −0.3 V to 0.1 V. The tolerance to the methanol crossover effect in alkaline media is superior. The Fe-N-CNT@GN catalyst obtained by this method solves the problem of agglomeration, migration, dissolution and leaching of catalysts in alkaline media. This type of catalyst has great potential for use as a high-performance nonprecious metal cathode catalyst in PEMFCs.

Latent heat storage mainly uses the latent heat of phase change material (PCM) to realize thermal energy storage and utilization, which is the most important thermal energy storage method at present. However, most of PCMs have the disadvantage of low thermal conductivity, which greatly restricts the thermal response rate and system efficiency of the thermal energy storage system. With the development of nanotechnology, it is expected to improve the thermal conductivity of traditional PCMs by adding high thermal conductivity nanoparticles. In this paper, a novel two-dimensional carbon nanomaterial, graphene is selected as an additive for PCM. In this paper, graphene nanoplatelets-octadecane phase change composite materials are prepared with a two-step method and the mass fractions of graphene nanoplatelets are 0%, 0.5%, 1%, 1.5%, and 2%. Their microstructures, morphologies and thermophysical properties are characterized by scanning electron microscopy (SEM), infrared spectroscopy (IR), differential scanning calorimetry (DSC), and thermal conductivity analysis. The effects of the addition quantity of graphene nanoplatelets on the phase transition temperature, enthalpy, specific heat capacity, thermal conductivity and thermal stability of the composite PCM are compared. The experimental results show that the dispersion stability of the graphene nanoplatelets in the composite system is greatly improved by the addition of dispersant, and the system does not produce obvious agglomeration nor sedimentation after multiple phase transformation cycles. The graphene nanoplatelets still maintain good lamellar structure and homogeneous dispersion in the n-octadecane matrix, and no chemical reaction occurs in the composite process. Comparing with the n-octadecane, the melting point of the composite phase change material decreases slightly, and the freezing point increases slightly. With the increase of graphene nanoplatelets, the latent heat value of graphene nanoplatelets-octadecane composite phase change material decreases gradually. For the composite phase change material with 2.0 wt.% graphene nanoplatelets, the melting enthalpy and solidified enthalpy are reduced by 6.01% and 7.35%, respectively. When the mass fractions of graphene nanoplatelets are 0.5%, 1%, 1.5%, and 2%, the thermal conductivity values of phase change composite materials are nearly 32.4%, 77.4%, 83.1%, and 89.4% higher than the thermal conductivity value of pure octadecane, respectively. Comparing with the significant increase in thermal conductivity, the addition of graphene nanoplatelets has little effect on the phase transition temperature and latent heat of PCM, and still exhibits the good heat storage performance.

The researchers of liquid detergent are most focused on detergency in the past, and the research on antibacterial activity of liquid detergent is rare. This research choose famous and common brands liquid laundry detergent in the market and studied their antimicrobial properties, test their antibacterial properties on the surface of the natural fiber fabric about Staphylococcus aureus (positive) and Escherichia coli (negative), analysis the antibacterial effect of the various brands, and the consumers have more reliable basis for purchase such goods. The antibacterial rate of liquid detergent against Galanz negative bacteria (E. coli) is generally higher, but the antibacterial rate against Galanz positive bacteria (S.aureus) is not good. The brand of Lan Yue Liang has excellent performance in this experiment, the antibacterial rate against E. coli and S.aureus reached to 96.25% and 95%.

Based on the surface microstructure of EB-PVD ZrO 2 coatings, the ablation effects of a novel method for ceramic modification technique by high-intensity pulsed ion beam irradiation have been studied numerically. Taking the nonlinear depositing energy of ions in the coatings calculated by Monte Carlo methods as the thermal source term in heat transfer equations, the surface melting process and the evolution of temperature of ZrO 2 specimens induced by HIPIB irradiation were obtained. About 1 μm in thickness of ZrO 2 ceramic was re-solidified after melting, a dense modification coat layer formed, and near the top surface an even denser layer formed. During the calculation the latent heat of ZrO 2 is introduced to consider the additional heat due to the phase change between solid–liquid and liquid–gas states. The numerical result about the ablation melted thickness of surface layer is in reasonable agreement with those measured by HIPIB irradiation experiments.

Thermal barrier coatings (TBCs) fabricated by electron-beam physical-vapor deposition (EB-PVD) were irradiated by high-intensity pulsed ion beam (HIPIB) at an ion current density of 100 A/cm2 with a shot number of 1-10. Microstructural features of the irradiated EB-PVD TBCs were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. All the HIPIB-irradiated EB-PVD TBC surfaces present smooth and densified features. The originated intercolumnar channels growing out to the top-coat surface and nanometer-scale gaps inside each single column were sealed after the remelting of TBC surface induced by HIPIB, resulting in formation of a continuous remelted layer about 1-2 μm in thickness. The dense remelted layer can work as a barrier against the heat-flow and corrosive gases, and gives the possibility of improving thermal conductivity and oxidation resistance of the HIPIB irradiated EB-PVD TBC.

Droplet behavior from the surfaces of pure metals Ti and Al ablated by high-intensity pulsed ion beam (HIPIB) with an ion current density from 30 to 200 A/cm2 has been investigated to explore the mechanism of mass transfer on HIPIB-irradiated materials. Droplet ejection on the ablated metal surface is studied by scanning electron microscope observation, energy dispersive X-ray spectroscopy analysis and profilometer measurement. The presence of ejected droplets from the irradiated surfaces is detected on both the surfaces of irradiated metals and substrates locating adjacent to the ablated surfaces. Moreover, the number density of droplets observed on both the surfaces tends to increase with increasing the ion current density. This phenomenon correlates to the fact that higher ion-beam intensity led to a more intense ablation, i.e. a severer droplet ejection. In addition, surface roughness (Ra) for the respective metals is continuously increased with increasing the ion current density, indicating a more significant disturbance on the melted surfaces caused by the correspondingly severer droplet ejection. Combined with the previous finding of selective ablation on titanium, it is concluded that the droplet ejection is the efficient cause of cratering and disturbance on HIPIB-ablated surfaces.

A hyperburner of a TBCC works in a wider operation range than an afterburner or a ramjet combustor. To meet the rigorous operation condition of a large bypass ratio engine under the whole flight range, core and the bypass flow should be mixed thoroughly. In this paper a lobe mixer for hyperburner was designed. Flow field and fuel distribution downstream the lobe mixer were studied by numerical simulation, and the characteristics of the lobe mixer was evaluated. Also, hyperburner combustion performance under different injection pattern was discussed. The results show that the streamwise votex created by the lobe can not only promote core and bypass flow mixing but also supply a more uniform fuel concentration. Staggered fuel injection from the both sides of lobe mixer radial can supply homogeneous fuel-air mixture for combustion, thus improve the hyperburner ignition characteristics and speed up the flame spreading procedure. The fuel injected from the lobe mixer outlet is benefit for the hyperburner performance.

A high-intensity pulsed ion beam (HIPIB) technique is applied to heat flux testing of plasma facing materials for fusion experiment. The HIPIB is generated at a relatively stable power density up to 10 W/cm, which covers a heat flux parameter of up to several hundreds MW m−2 s. Surface morphology and weight loss are examined for doped and coated graphite with HIPIB exposure of 280 MW m−2 s, being of the same order of thermal loads during off-normal events in future fusion reactors. The work demonstrates a first example utilizing the HIPIB technique to study thermal response of plasma facing materials under fusion relevant thermal loads.

ZrO 2 ceramic coatings, which often call thermal barrier coatings (TBCs), fabricated by electron beam physical vapor deposition (EB-PVD), are widely used in high-temperature environment of aircraft and industry gas-turbine engines, because of the excellent strain tolerance imparted by the columnar structure. However, channels separating the columnar grains in EB-PVD TBCs provide paths for oxygen or other aggressive species from ambient atmosphere into the bond coat, resulting in the premature spallation-failure during high-temperature service. In our previous study, high-intensity pulsed ion beam (HIPIB) technique has been proposed to modify the EB-PVD TBCs, where a melted, densified top layer can be produced as a result of extremely thermal effect induced by the HIPIB irradiation. In this paper, HIPIB melting process is investigated numerically using a physical model based on experimental data, taking into account the surface morphology of HIPIB-melted TBCs to explore the mechanism of interaction between HIPIB and the coatings. Deposition process of the beam energy in TBCs was simulated by Monte Carlo method, and the non-linear equations describing the thermal conducting process were solved numerically based on the deposited energy to obtain the evolution of the temperature field of TBCs. The calculated melting depth of irradiated EB-PVD TBCs is consistent with results obtained in the HIPIB irradiation experiments.

A novel shock processing by high-intensity pulsed ion beam (HIPIB) is developed, referred to as ion beam shock processing (IBSP), for surface processing of components with high surface integrity. The IBSP utilizes effectively coupled thermal-dynamic effects of HIPIB irradiation onto materials, characterized by ultrafast surface remelting and solidification, and controlled ablation. As a result, using the IBSP treatment with HIPIB parameters with an ion energy of 200–400 keV and an ion current density of 50–400 A/cm2 with a pulse width of 75 ns, i.e., a power density of 107–108 W/cm2, hardening extending to tens and hundreds of micrometers in depth is achieved on pure Cu and 316L austenitic stainless steel, which is comparable to that of laser shock processing at about two orders higher power density, usually no less than 109–1010 W/cm2. Significant improvements in the overall performance including wear and corrosion resistance, fatigue, and creep properties are found for IBSP treated pure Cu and 316L stainless steel, attributable to the formation of nonequilibrium microstructures into different depths of the processed materials, e.g., amorphous and/or nanocrystalline structure in the heat-affected zone, and high-density defects in the deeper regions with residual compressive stresses caused by shock wave propagation into substrate in which the former is not obtainable in conventional shock processing. Furthermore, purified and polished surfaces free of cracks can be obtained simultaneously under HIPIB irradiation, composing the completeness for effectively enhancing the surface integrity of the processed materials. The coupled thermal-dynamic effects of IBSP assure surface processing of high surface integrity for components, with improved physical and chemical properties and modified surface topography.