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The development of new composite materials with micro- and nanostructures and the realization of rapid transmission of lithium ions are crucial for the high-performance anode materials of lithium-ion batteries. Cobalt-based composites have received considerable attention on account of their unique physicochemical properties and good electrochemical performance. Therefore, it is of great significance to synthesize new Co-based composites and to research their electrochemical properties. In this work, nanoneedle CoOHF was successfully loaded on N-doped porous carbon (CoOHF/N–C) by facile sintering and hydrothermal method for the first time, which possessed excellent cycle stability and fast lithium-ion transport kinetics. The special porous structure in CoOHF/N–C can effectively alleviate the volume effect of CoOHF during cyclic charging and discharging, and the nanoneedle CoOHF presents a flower-like structure, which can also provide a large specific surface area, which ensures more active sites and shorter diffusion paths for rapid Li+diffusion, thus offering a larger electrode/electrolyte interface for charge transfer. Under these synergistic effects, the CoOHF/N–C anode has excellent electrochemical performance, including an admirable initial discharge capacity of 1203.7 mAh g–1at 200 mA g–1, a high reversible capacity of 913.3 mAh g–1after 300 cycles, and a high Li+diffusion coefficient, ensuring improved cycling stability and rate performance. This work opens up the possibility of novel ways of designing new Co-based nanoanode materials for high-performance lithium-ion batteries.

• A high-tortuosity holey graphene was successfully prepared based on the unique flake structure and chemical composition of cytomembrane and cytoderm. • Benefiting from the unique nanoholes shortening the ion-diffusion length, the synergy of wrinkled and holey structure stabilizing volume fluctuation, the enhanced electronic conductivity and specific surface area. • The anode achieves excellent reversible capacity, and exceptional rate capability with an ultra-long cycle lifespan in PIBs. • The anode exhibits a high energy density as well as considerable cycling stability for potassium-ion full cells. The sluggish K+ kinetics and structural instability of the generally-used graphite and other carbon-based materials hinder the development of potassium-ion batteries (PIBs) for high-rate capability and long-term cycling. Herein, inspired by the unique flake structure and chemical composition of cytomembrane and cytoderm, we design high-tortuosity holey graphene as a highly efficient anode for PIBs. The flake cytomembrane and cytoderm shrink into wrinkled morphology during drying and sintering and then convert into high-tortuosity graphene after oxidative exfoliating and thermal reducing process. Meanwhile, the proteins, sugars, and glycolipids embedded in cytomembrane and cytoderm can in-situ form nanoholes with highly abundant oxygenic groups and heteroatoms around, which can be easily removed and finally the high-tortuosity holey graphene is obtained after a thermal reducing process. The stress distribution after K+ intercalation confirms the optimized release of strain caused by the volume change through the finite element method. Benefiting from the unique nanoholes shortening the ion-diffusion length, the synergy of wrinkled and holey structure stabilizing volume fluctuation, and the enhanced electronic conductivity and specific surface area, the high-tortuosity holey graphene demonstrates high reversible capacities of 410 mAh g–1 at 25 mA g–1 after 150 cycles and retains 91.5% at 2 A g–1 after 2500 cycles. [Display omitted] [ABSTRACT FROM AUTHOR]

•Plant SINAgenes likely originated before the divergence of bryophyte and gave rise to two clades.•Genes gains and losses occurred leading to an increase in number of SINAgene copies in angiosperms.•The Gossypium SINAsshowed a tendency for expansion via whole-genome duplication and polyploidy.•The diversity of SINAs might correlates with evolution to adapt to environment stress.

Potassium ion batteries, due to their similar electrochemical principles to lithium-ion batteries and the abundance of metal sources, are considered one of the alternatives to lithium-ion batteries. The development of new cathode materials has always been a research focus in this field. Among them, Prussian blue materials, with their three-dimensional open and flexible metal framework structure, can efficiently and reversibly store potassium ions. However, Prussian blue cathode materials still face issues such as poor reversibility and low capacity, which limit their application scope. This study investigates the preparation of high-entropy Prussian blue analogues materials to enhance electrochemical performance. The doping of five different transition metals (Fe2⁺, Co2⁺, Cu2+, Ni2+, and Mn2+) sharing the same nitrogen coordination sites results in a configurational entropy greater than 1.5 R for the material. HEPB-1 cathode material (K1.75Mn0.26Fe0.01Ni0.01Cu0.08Co0.09[Fe(CN)6]0.66·0.83H2O) shows better electrochemical performance, with the initial discharge capacity of 86.69 and 74.51 mAh g−1(capacity retention is 75.2% after 100 cycles) at 20 and 100 mA g−1, respectively. The research results have provided new insights for the further development and application of potassium ion batteries.

The development of flexible smart phase change fibers has been limited because of the low production rate and safety concerns of electrospinning. Therefore, a novel centrifugal spinning technology, which is a safe and large-scale fabrication approach, is employed to extrude flexible smart phase change fibers using polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP). Nano-Al2O3was employed to enhance the thermal conductivity of flexible smart PEG/PVP phase change fibers. The flexible smart PEG/PVP/Nano-Al2O3phase change fibers have a clear cylindrical fiber shape, no cross-linking, and uniform fiber axial distribution. The interactions in flexible smart PEG/PVP/Nano-Al2O3phase change fibers involve physical loading in PEG, PVP, and Nano-Al2O3. The flexible smart PEG/PVP/Nano-Al2O39.0% phase change fibers have a latent heat of 50.7 J/g at the melting point of 46.7 °C. The flexible fibers have ideal thermal stability and thermal cycle stability, and the shape of flexible fibers remained stable during the phase-change process. The thermal conductivity of flexible smart PEG/PVP/Nano-Al2O39.0% phase change fibers was 3.05 times greater than that of PEG/PVP fibers. The flexible smart fibers are promising for applications in the field of thermal insulation.

As an electrolyte additive, the acidified cellulose ester has been demonstrated to be effective in inhibiting lithium dendrite growth and improving the coulombic efficiency of lithium metal batteries.

Flexible electrodes have broad applications in microelectronics. In this work, flexible electrodes were fabricated through chemically induced joining of silver nanoparticles at room temperature. After the joining process, the resistance of the silver track decreased by 8 orders of magnitude. The joining parameters were systematically investigated including the concentration of the chemical solution, sintering time, and drying temperature. This chemical method achieved the same effect at room temperature as compared to the methods using thermal sintering. The changes of the microstructure and the surface composition of silver nanoparticles were characterized to better understand the nanojoining process at room temperature.

Electrode materials that act through the electrochemical conversion mechanism, such as metal selenides, have been considered as promising anode candidates for lithium-ion batteries (LIBs), although their fast capacity attenuation and inadequate electrical conductivity are impeding their practical application. In this work, these issues are addressed through the efficient fabrication of MnSe nanoparticles inside porous carbon hierarchical architectures for evaluation as anode materials for LIBs. Density functional theory simulations indicate that there is a completely irreversible phase transformation during the initial cycle, and the high structural reversibility of β-MnSe provides a low energy barrier for the diffusion of lithium ions. Electron localization function calculations demonstrate that the phase transformation leads to high charge transfer kinetics and a favorable lithium ion diffusion coefficient. Benefitting from the phase transformation and unique structural engineering, the MnSe/C chestnut-like structures with boosted conductivity deliver enhanced lithium storage performance (885 mA h g–1at a current density of 0.2 A g–1after 200 cycles), superior cycling stability (a capacity of 880 mA h g–1at 1 A g–1after 1000 cycles), and outstanding rate performance (416 mA h g–1at 2 A g–1).

Abstract

Bismuth (Bi)-based photocatalytic materials are widely used in the field of photocatalytic degradation of wastewater. In this study, β-Bi2O3/BiOBr heterojunction photocatalysts were prepared by an in situ chemical transformation method. BiOBr molecules are arrayed to cross each other to form a pore around β-Bi2O3. The prepared photocatalyst had a large specific surface area and excellent adsorption and photocatalytic properties. The β-Bi2O3/BiOBr with a molecular ratio of 11.1% had the highest catalytic activity. The result of a degradation experiment, performed with Rhodamine B (RhB) as the target pollutant, revealed that the degradation rate reached 99.85% after 25 min under visible light irradiation. The pore structure can adsorb contaminants and the heterojunction facilitates the separation of photogenerated electron–hole pairs to enhance the photocatalytic properties. The high adsorption performance and heterojunction achieved higher photocatalytic efficiency. This semiconductor photocatalyst with high adsorption performance provides a new approach to control water pollution.

It is highly desirable to red shift the emission of Y3Al5O12:Ce3+phosphor to obtain a warmer correlated color temperature (CCT) in applications for blue-light pumped white-light emitting diodes (w-LEDs) with high color rendering index (CRI). In this paper, we report the red-shifted emission of Y3MgSiAl3O12:Ce3+garnet phosphor for w-LEDs through a chemical unit cosubstituting in a solid solution design strategy. The fabrication temperature of the Y3MgSiAl3O12:Ce3+powder was optimized at 1600 °C, and its structure, photoluminescence property, micromorphology, decay curve, quantum yield, as well as the thermal stability of the samples are investigated in detail. The as-prepared Y3MgSiAl3O12:Ce3+phosphors display a broad excitation band ranging from 300 to 520 nm (centered at 450 nm) and present an intense Ce3+5d–4f emission band in the yellow light region (λem= 564 nm, obviously red-shifted away from Y3Al5O12:Ce3+). This can be explained by the increase of the crystal-field splitting in the Ce3+5d levels owing to the chemical unit cosubstitution of Al3+(I) and Al3+(II) ions by Mg2+and Si4+ions. The quantum yield of the Y2.92MgSiAl3O12:0.08Ce3+phosphor is measured as 61.8%. Further investigation on a lamp packaged w-LEDs combining Y2.92MgSiAl3O12:0.08Ce3+phosphors on a blue InGaN chip shows it to exhibits a lower CCT and higher CRI compared to those of the commercial Y3Al5O12:Ce3+-based devices, indicating their appealing strengths for potential applications in w-LEDs.

A novel porous silicon was synthesized through a magnesiothermic reduction method of molecular sieve for the first time, the porous silicon was used as anode material, which shows a high initial specific capacity of 2018.5mAh/g with current density of 0.1A/g.

A series of luminescent Ba0.79Al10.9O17.14:xEu (x= 0.005–0.12) phosphors were prepared by high-temperature solid-state reaction in air atmosphere. The coexistence of Eu2+and Eu3+was observed and verified by photoluminescence (PL) and photoluminescence excitation (PLE) spectra, X-ray photoelectron spectra (XPS), and diffuse reflection spectra. The band emission peaking at 430 nm was assigned to 4F65D–4F7transition of Eu2+, and another four emissions peaking at 589, 619, 655, and 704 nm were attributed to 4F–4F transitions of 5D0–7FJ(J= 1, 2, 3, 4) of Eu3+. The related mechanism of self-reduction was discussed in detail. The color of the Ba0.79Al10.9O17.14:xEu phosphors could be shifted from blue (0.23, 0.10) to red (0.42, 0.27) by doping Li+ions, and the temperature dependence properties were investigated.

Codoping with Li+is a prevalent strategy to improve the optical efficiency of luminescent materials, while the mechanisms of enhancement are still ambiguous. Herein, we delineate the major ways by which Li+enhanced the emission of orthophosphate phosphor KMg4(PO4)3:Eu2+and quantify the relative contributions of each mechanism. Results from X-ray diffraction, scanning electron microscopy, and steady-state and time-resolved fluorescence spectroscopies show that the 3.8-fold increase in emission intensity caused by optimized Li+doping was attributed to flux effect (∼30.84%), crystal-field splitting (∼5.30%), and a reduction in concentration quenching (∼63.86%), respectively. The as-synthesized materials also show excellent thermal stability and an increased internal quantum efficiency of 84.02% compared with 53.13% of nondoped phosphors. The white light emitting diodes employing KMg4(PO4)3:Eu2+,Li+as a blue-emitting component exhibit superior electroluminescence properties. The above results demonstrate that introducing Li+ions can obviously enhance the luminescence efficiency of KMg4(PO4)3:Eu2+phosphor.

The proton exchange membrane fuel cell (PEMFC) is a fast growing next-generation energy conversion technology, which has broad application prospects in electric vehicles, such as portable power supplies, fixed power supplies, and the military industry. The development of PEMFCs has attracted much attention due to their high energy conversion efficiency, good low-temperature startup performance, no pollution, no noise, and other advantages. However, the cathodic oxygen reduction reaction (ORR) kinetics in fuel cells is slow. It is therefore necessary that we use a large number of carbon-supported platinum (Pt)-based catalysts in order to speed up the reaction. As a result, the current problems of high cost and low durability of carbon-supported Pt-based catalysts have become a major reason for limiting the successful commercialization of fuel cells. To meet the requirements of high catalytic activity and high stability of carbon-supported Pt-based catalysts, this review summarizes the research progress and methods for optimizing the performance of carbon-supported Pt-based catalysts for PEMFCs. In addition, this review highlights the current progress in improving the performance of carbon-supported Pt-based catalysts in terms of the reduction of particle size, exposure of highly active crystal surfaces, control of Pt particle morphology, and preparation of Pt–M alloys as well as some support characteristics and preparation technologies. Furthermore, the development of carbon-supported Pt-based catalysts in the direction of fuel cells and the main challenges they will face in practical applications are also proposed in this review. In summary, the carbon-supported Pt-based catalysts optimized using the above methods show great potential in the ORR. With continuous improvement of preparation and characterization technologies, carbon-supported Pt-based catalysts have broad applications and market prospects.

Electric heating, as a kind of clean heating approach, has aroused worldwide interest due to its exceptional energy conservation, high efficiency, and random switching modulation. However, it is still a great challenge on the practical application of carbon-based electrothermal composites, since the degradation of material long-time operation performances caused by the agglomeration of carbon fillers and the aging of polymer substrates. Herein, we propose a novel porous carbon fiber foam connected by the inorganic compound aluminum phosphate (CKFC), based on the kapok fibers via a vacuum impregnation and carbonization process. The additive agent, including aluminum dihydrogen phosphate and iron(III) chloride hexahydrate, could help to maintain the hollow cylindrical structure, produce more micropores in the carbon fibers, and ensure the fibers are firmly bonded together. The hierarchical carbon fiber structure and strong interfacial interactions endow the CKFC composite with fast heating response speed, high balance temperature under low input voltages (below 36 V), uniform surface temperature distribution, and desirable service stability during the electric heating. Impressively, the further prepared CKFC/paraffin composite exhibits an ultrahigh heat storage efficiency (97.9 %), which could also quickly raise the temperature to 45 °C within safety voltage and delay the heat release. Therefore, we believe that the CKFC/paraffin composite with excellent electric heating and electric thermal storage performances could hold great promise for the practical application in electric indoor heating.

A series of Gd5Si2BO13:Eu3+and non-rare earth Bi3+ions doped Gd5Si2BO13:Eu3+phosphors were successfully synthesized via high-temperature solid-state method, and the as-obtained phosphors were studied for their phase structures, luminescence characteristics, thermal stability and luminescence lifetime. Transient fluorescence spectroscopy data show that the addition of Bi3+can obviously enhance the emission intensity of Eu3+in the near-ultraviolet band owing to energy transfer from Bi3+to Eu3+. Besides, the addition of Bi3+can improve the thermal stability of a single-doped phosphor Gd5Si2BO13:0.35Eu3+from 70.33% to 87.45% at 150 oC and the quantum yield from 58.80% to 78.61% at room temperature. Finally, Gd5Si2BO13:Eu3+,Bi3+was used to encapsulate WLED with green ((Ba,Sr)2SiO4:Eu2+) and blue (BaMgAl10O17:Eu2+) commercial phosphors. The color rendering index of WLED was calculated to be larger than 90, and the color temperature is estimated to be 4300-4500 K, which demonstrates that Gd5Si2BO13:Eu3+,Bi3+can be regarded as a red phosphor with great potential application. This paper can provide a new insight to design high-efficiency phosphors by introducing non-rare earth Bi3+ions via energy transfer from Bi3+to Eu3+.

Abstract: An Al2O3 ceramic coating (A), a 13 wt.% TiO2-Al2O3 (13TA) composite ceramic coating, and a Ni-Al-13wt.%TiO2-Al2O3 (NA-13TA) gradient composite ceramic coating were prepared on Q235 steel by plasma spraying. The corrosion behavior of samples sprayed with these coatings in a boiling 5% HCl solution was investigated. It was shown that an A ceramic coating and a 13TA composite ceramic coating were destroyed after immersion for 17 and 23 h, respectively. The NA-13TA gradient composite ceramic coating was still sound after 14 days of immersion. The corrosion resistance of samples with the NA-13TA gradient composite ceramic coating was sharply improved due to the decreased amount of connected pores in the coating. The corrosion of the sample sprayed with the gradient ceramic coating included the partial corrosion of the surface ceramic coating and the interlayer coatings. The corrosion weight loss depended on the degree of open porosity.

A power generator based on carbon nanoparticles and TiO2nanowires was fabricated by sequential electrophoretic deposition.Benefit from the special structure of the carbon nanoparticle films, the generator exhibited an fast and reliable response to liquids.A possible system for printed circuit board protection using an array of power generators was proposed.