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To advance the understanding of the degradation of the liquid electrolyte and Si electrode, and their interface, we exploit the latest developments in cryo-atom probe tomography. We evidence Si anode corrosion from the decomposition of the Li salt before charge-discharge cycles even begin. Volume shrinkage during delithiation leads to the development of nanograins from recrystallization in regions left amorphous by the lithiation. The newly created grain boundaries facilitate pulverization of nanoscale Si fragments, and one is found floating in the electrolyte. P is segregated to these grain boundaries, which confirms the decomposition of the electrolyte. As structural defects are bound to assist the nucleation of Li-rich phases in subsequent lithiations and accelerate the electrolyte's decomposition, these insights into the developed nanoscale microstructure interacting with the electrolyte contribute to understanding the self-catalyzed/accelerated degradation Si anodes and can inform new battery designs unaffected by these life-limiting factors.

Solid-state fiber dye-sensitized solar cells (SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal-organic frameworks (MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency (PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO2 (mp-TiO2) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices (4.19%). The MOF-801 enhanced SS-FDSSCs decreased the series resistance (Rs) value, resulting in effective electron extraction with improved short-circuit current density (JSC), while also increasing the shunt resistance (Rsh) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.

Powder processing by ball milling is an effective approach for materials engineering. Although various methods for material processing are available, only high-energy shaker/vibratory or planetary mills have been intensively utilized to develop mechanical milling or alloying routes for structural control of MgB2 superconducting materials. Herein, we have attempted structural modification by using a low-rotation shaker, which is categorized as a low-energy and economical mill in terms of industrial applications. The operation speed was kept constant at 40 rpm, which is much lower than typical conditions employed for planetary mills. Instead of adjusting the low rotational speed, the other processing parameters were controlled to enhance the energy transfer from the balls to powders. The applied milling conditions were ultimately found to cause severe plastic deformation of the raw powders. The shape and size changed drastically, depending on the processing time. The morphological variation of the processed powders as precursors for the MgB2 materials influenced the void structure and the composition including amorphous phases. By considering these results, we also elucidated the mechanism underlying the structural changes upon ball milling and their effects on the transport critical current performance. The present approach for powder processing offers potential as an effective milling route for structural modification of superconducting materials.

We investigated the optical and electrical properties of Ta2O5/Ag/Ta2O5 films as functions of the thicknesses of the Ta2O5 and Ag layers. It was found that with an increase in the thicknesses of the Ta2O5 and Ag layers from 10 to 40 nm and from 12 to 24 nm, respectively, the sheet resistance, carrier concentration, electron mobility, and resistivity of the Ta2O5/Ag/Ta2O5 film varied from 2.02 to 8.95 Ω/sq, 5.74 × 1021 to 2.92 × 1022 cm–3, from 13.21 to 24.07 cm2/V·s, and from 8.89 × 10-6 to 8.24 × 10-5 Ω cm, respectively. The average transmittance (Tav) of the multilayer samples ranged from 57.18% to 93.99%, and it depended on the Ta2O5 and Ag layer thicknesses. The highest Tav of 93.99% was observed for the film with 35 nm thick Ta2O5 and 18 nm thick Ag layers, and the peak Haacke's figure of merit (157.04 × 10–3 Ω–1) was obtained for 20 nm thick Ta2O5 and 21 nm thick Ag layers. Ta2O5 (100 nm) and Ta2O5/Ag/Ta2O5 (20 nm/21 nm/20 nm) samples had optical bandgaps of 4.70 and 4.45 eV, respectively. Film Wizard simulations were conducted to understand the dependence of the transmittance of the multilayer on the thicknesses of the Ta2O5 and Ag layers, and phasor analyses were performed to determine how the transmittance of the Ta2O5/Ag/Ta2O5 (20 nm/21 nm/20 nm) film depended on the Ta2O5 layer's thickness.

Na3V2(PO4)3 (NVP) is a member of the sodium superionic conductor (NASICON) family and has been extensively studied as a cathode material for sodium-ion batteries (SIBs) for more than three decades due to its stable voltage platform, high capacity, and stable cycle life. However, the presence of toxic and expensive V elements restricts the utilization of NVP-based SIBs. To overcome this, energy researchers have employed a cation swapping approach, which resulted in new NASICON-type manganese-substituted sodium vanadium phosphate (MSVP) cathodes for SIBs. Na4MnV(PO4)3 (NMVP) is among the new generation of high-energy, risk-free NASICON-type MSVP cathodes, and its use for SIBs was documented in 2016. There has been strong acceptance of MSVP-based cathodes among materials researchers due to their cost and economic advantages. In a short period, considerable work has been done to increase the commercial potential of MSVP-based cathodes for SIBs. This review summarizes the pioneering developments made with MSVP-based cathodes, with a special focus on their structural and electrochemical evolution. This review can serve as a reference for future energy researchers fabricating highly efficient and safer NASICON cathodes not only for SIBs but also for other energy storage applications.

Transition metal dichalcogenide (TMD) monolayers, such as MoS2, possess a direct optical bandgap and are useful for emerging ultrathin optoelectronics in the visible light range, whereas their thickness limits light absorption and emission properties. To address this drawback, one promising approach is to hybridize plasmonic nanostructures with monolayer TMDs to utilize local field enhancement effects owing to localized surface plasmon resonance (LSPR). Herein, we propose a strong enhancement of the local light–matter interaction in MoS2 monolayers on naturally generated nanoscale grooves. The nanogrooves are formed at grain boundaries (GBs) of template-stripped metal film substrates that are fabricated by mechanically stripping Ag films deposited on an ultra-flat Si substrate, wherein the nanogroove densities are systematically modulated by the Ag film thickness. We observe an effective photoluminescence enhancement factor of 758 and a Raman spectroscopy intensity enhancement of approximately 5 times in MoS2 on the subwavelength-scale nanogrooves, compared with that on grain planes, which is attributed to a strong local field enhancement of the LSPR effect. Moreover, this plasmonic enhancement effect is elucidated by dark-field scattering spectroscopy and optical simulations. Our results can facilitate the utilization of density-controllable plasmonic nanogrooves synthesized without nanopatterning techniques for plasmonic hybrids on 2D semiconductors.

Many researchers working on the development of Dye-sensitized solar cells (DSCs) continue to focus on the synthesis of photoanode materials with high surface area, along with high light scattering ability to enhance light harvesting efficiency (LHE). On the other hand, dye packing density, which can also affect the LHE significantly, is often overlooked. Solvothermally synthesized anatase TiO2 nanoparticles (SANP) were obtained by a new and simple approach using a mixed solvent, ethanol and acetic acid. SANP were applied as a photoanodes material in DSCs using a metal-free organic dye (D149) or organometallic dye (N719) dyes. The dye loading (packing density) was examined in term of the isoelectric point (IEP) and the contribution of this, in addition to light scattering effects were shown to control the devices photovoltaic efficiency of the devices; specifically when compared with ones employing commercially available TiO2 nanoparticles (either transparent or a bilayer structure with a transparent layer and a scattering one). SANP photoanodes sensitized with D149 dye were found to be optimised at 10 µm, yielding photovoltaic conversion efficiencies of 6.9%, superior to for transparent or transparent + scattering films from the commercial source (5.6% and 5.9%, respectively). Further to this, an efficiency of 7.7% PCE was achieved using a SANP photoanode sensitized with N719 dye, with 7.2% seen for the transparent photoanode and 7.9% with a scattering layer. The high efficiencies of devices based on of SANP photoanode are attributed to the high dye loading capability in addition to good light scattering. A further point of interest is that even with the increased reactivity of the surface towards dye adsorption, we did not observe any significant increase in recombination with the redox mediator, presumably due to this increased dye loading providing better shielding.

This paper reports the first demonstration of super broadband infrared downshifting emission extending from 1640 ​nm to 2200 ​nm with the full width at half maximum of ∼ 417 ​nm in lanthanides (Er3+, Ho3+, and Tm3+)-doped α-SiAlON ceramics upon 793 ​nm excitation. Using α-Si3N4 ceramic as a precursor the lanthanides-doped α-SiAlON ceramics were synthesized by the hot-press method. The lanthanides induced no significant secondary phases in the sintered α-SiAlON ceramics. Strong two-photon upconversion emission bands centered at 547, 671 and 694 ​nm have also been observed upon 793 ​nm excitation. The time-resolved measurements of the upconversion emissions confirm that the efficient energy transfer among the Er3+, Ho3+ and Tm3+ ions as well as the ground state absorption in Er3+ and Tm3+ are responsible for the observed spectroscopic properties.

In this study, two-channel thin-film transistors (TC TFTs) using sputtered-deposited amorphous indium-gallium-zinc oxide (a-IGZO) as a channel layer and atomic-layer-deposition Al₂O₃ as gate insulator (GI) are proposed for wearable and portable device application. Symmetric-TC (S-TC) TFT structure consisted of conventional bottom gate (BG) TFT stacked on top of top gate (TG) TFT. Asymmetric-TC (A-TC) TFT contained BG TFT with tandem structure on the TG TFT. It was shown that the TC TFTs exhibited excellent performance such as high field-effect mobility ( $μ_{FE}$ ) and on/off current ratio ( $I_{t{on/off}}$ ) at low voltages (

Grinding aids to increase grinding efficiency in cement production are materials that can produce large amounts of high-quality cement in a short time by reducing surface energy by preventing particle agglomeration and improving fluidity. In the paper, a grinding aid using glycerol-waste antifreeze(GAP) is prepared and its effect on the grinding properties of clinker is investigated in contrast to that without the grinding aid. The results are as follows: The angle of repose of the cement powder added with GAP decreases as the grinding time increases (decreases by 3.8° when the grinding time is 60 minutes), indicating that it increases the flowability of the powder. On the contrary, the residual amount of 45µm sieve is also significantly reduced (4.6% decrease) and the specific surface area increases (30.5m2/kg), which results in an increase in the grinding efficiency. In the size range of 3 to 32µm, it increases the particle content, makes the particle size distribution uniform, the 7d and 28d activity index of the powder is improved by 5% and 6%, respectively, and increases the compressive strength of the cement. In addition, it is confirmed that the performance of the TEA grinding aid and the grinding aid are similar, and are very effective in terms of economy.

The surface of polycarbonate (PC) was fluorinated with a mixed gas of F2 and O2 at 25 °C for 1 h. The surface roughness (Ra) of the fluorinated PC samples was about double that of the untreated sample (0.685 nm), while the water contact angle of the fluorinated PC samples decreased from 80° to 12°. The dyeing properties of the PC surface were enhanced after surface fluorination due to the increased roughness and hydrophilicity. Fluorination using a mixed gas with a higher F2 proportion led to the formation of a thicker dyeable fluoride layer, thereby giving a deeper color after staining of the PC surface.

Deformable 3D structures have emerged to revolutionize next-generation flexible electronics. In this study, a large out-of-plane deformable kirigami-based structure integrated with traditional functional materials has been successfully applied to wirelessly sense mechanical vibration and pressure. Unlike spiral inductor coils that lack mechanical stability, the inductor coils supported with polymer kirigami designs, comprising concentric circles with alternately connected hinges among the consecutive layers, offer exceptional mechanical stability. The wireless sensor shows a good linear response (Adj. R2 = 0.99) between the shift in resonant frequency as a function of extension. Moreover, the sensor device exhibits excellent cycling mechanical stability and minimal hysteresis, as confirmed by the experiments performed for over 5 d. An acceleration sensor (0-20 ms-2) with high linearity (Adj. R2 = 0.99) is introduced. Furthermore, a highly sensitive low-pressure sensor is demonstrated wirelessly in real time. Thus, the sensor can wirelessly monitor mechanical vibration and pressure. It can be applied for motion tracking, health monitoring, soft robotics, and deformation detection in battery-free deformable electronic devices.

Epithelial ovarian cancer is a gynecological cancer with the highest mortality rate, and it exhibits resistance to conventional drugs. Gold nanospheres have gained increasing attention over the years as photothermal therapeutic nanoparticles, owing to their excellent biocompatibility, chemical stability, and ease of synthesis; however, their practical application has been hampered by their low colloidal stability and photothermal effects. In the present study, we developed a yolk-shell-structured silica nanocapsule encapsulating aggregated gold nanospheres (aAuYSs) and examined the photothermal effects of aAuYSs on cell death in drug-resistant ovarian cancers both in vitro and in vivo. The aAuYSs were synthesized using stepwise silica seed synthesis, surface amino functionalization, gold nanosphere decoration, mesoporous organosilica coating, and selective etching of the silica template. Gold nanospheres were agglomerated in the confined silica interior of aAuYSs, resulting in the red-shifting of absorbance and enhancement of the photothermal effect under 808 nm laser irradiation. The efficiency of photothermal therapy was first evaluated by inducing aAuYS-mediated cell death in A2780 ovarian cancer cells, which were cultured in a two-dimensional culture and a three-dimensional spheroid culture. We observed that photothermal therapy using aAuYSs together with doxorubicin treatment synergistically induced the cell death of doxorubicin-resistant A2780 cancer cells in vitro. Furthermore, this type of combinatorial treatment with photothermal therapy and doxorubicin synergistically inhibited the in vivo tumor growth of doxorubicin-resistant A2780 cancer cells in a xenograft transplantation model. These results suggest that photothermal therapy using aAuYSs is highly effective in the treatment of drug-resistant cancers.

Na-ion batteries and K-ion batteries are promising alternatives to vastly used lithium-ion batteries mainly due to the larger natural abundance of sodium and potassium resources. Carbon-based and MXene materials have received increasing attention due to their unique layered structure to accommodate the larger sodium and potassium ions. It’s proposed that ionic size disparity (K+: 1.38 A; Na+: 0.97 A; Li+: 0.76 A) leads to sluggish intercalation and extraction kinetics in larger alkali metal ions (AMIs). Nevertheless, the electrochemical inactivity of sodium intercalation in graphite suggests that different chemical properties of AMs and their interactions with carbon host and electrolytes is crucial for interfacial instability and irreversible capacity loss. Structural modifications by expanding interlayer spacing and defect engineering enable reduced diffusion barriers and enhanced insertion of sodium or potassium, but it blurs the electrochemical performance between battery and capacitor. This review provides insight into 2D carbon materials and their architectures for Na and K-ion batteries through an in-depth analysis of structure–property interdependence and different electrochemical mechanisms supported by both experimental and theoretical data to discuss the promises and challenges of post-lithium batteries. Finally, the perspectives and potential directions regarding material design concepts for 2D carbon-based nanomaterials and MXene phases for metal-ion storage are proposed.

Herein, we investigated the influence of sulfur (S) addition on the phase formation behavior and thermoelectric transport properties of n-type Cu0.008Bi2Te3. A complete single phase of rhombohedral Bi2Te3 was formed in Cu0.008Bi2Te2.8S0.2, whereas a mixture of Bi2Te3 and Bi2Te2S1 phases was generated at higher S contents. We elucidated the complex effects of S substitution at Te-site on transport properties of Cu0.008Bi2Te3; (1) increase in density-of-states effective mass, (2) decrease in weighted mobility ratio, (3) reduction in lattice thermal conductivity, and (4) reduction in bipolar thermal conductivity. Despite the slight deterioration in electronic transport properties, a maximum thermoelectric figure of merit (zT) of 0.82 was achieved at 400 K in Cu0.008Bi2Te2.8S0.2 due to the synergetic effect of intensified point defect phonon scattering in a wide temperature range and suppressed bipolar thermal conduction at elevated temperatures.

Compared with conventional hydrogen-air combustion, catalytic hydrogen combustion (CHC) exhibits higher safety and efficiency and ultra-low NOx emissions. Significant advances in CHC have been achieved in recent years through fundamental research. Therefore, the state-of-the-art CHC technology is comprehensively reviewed herein, including catalyst development, catalytic reactors, and the factors impacting the kinetics of various CHC systems. Furthermore, the progress made in CHC catalyst design over the years is examined, and detailed information regarding their synthesis, structure, and characteristics are presented. The comparison of several types of CHC reactors, including fixed-bed, monolithic, and microchannel reactors, is presented in terms of their operational features and performances. The effects of several operating parameters, including the reaction temperature, hydrogen-to-oxygen stoichiometric ratio, space velocity, residence time, and operating pressure, of the CHC processes are reviewed. The catalytic reaction pathways and the kinetics of the CHC processes are also summarized, advancing the understanding of the underlying chemistry on the catalyst surfaces. This review analyzes the various catalysts, reactor types, operating factors, and underlying mechanisms involved in CHC to better understand the mass transfer, heat transfer, and chemistry during this process. Finally, future research directions are proposed to explore the design of catalytic reactors for CHC.

Porous ceramics have the advantages of low density, low thermal conductivity, and excellent mechanical properties. One of the scalable methods for manufacturing porous ceramics is the replica method, which provides the advantage of high porosity and the critical disadvantage of low mechanical strength. To overcome this shortcoming, mullite (3Al2O3·2SiO2) whiskers, which have excellent thermal stability and high mechanical strength, were introduced in porous ceramic structure. The mullite whiskers were prepared using Al2O3, kaolin, frit, and MoO3 composition. The addition of MoO3 lowered the mullitization temperature, and the mullite whiskers could be grown at 1100–1400 °C. The morphologies and crystal structures of the mullite whiskers with various the annealing temperatures and MoO3 contents were investigated in detail. The mullite whiskers, which contained 20 wt% MoO3 and was annealed at 1300 °C, showed the highest aspect ratio of 137 with the average length of 46.6 μm and average thickness of 0.34 μm. The compressive strength and porosity of the porous ceramic sample with these mullite whiskers were 0.97 MPa and 87.5%, which were also the highest values.

We investigate the nanogap and polarization-resolved excitation of gap plasmon modes using terrace-stepped hexagonal boron nitride (hBN) sandwiched between Ag nanowires and Au substrates for a metal–insulator–metal gap structure. The gap plasmon modes in the proposed hybrid structure are dominantly excited by a P-polarized incident light, which is supported by full-wave numerical simulations. Plasmon mode evolution for various hBN spacer thicknesses ranging from 5 to 90 nm shows that optical signals acquired via unpolarized dark-field mapping spectroscopy are primarily due to the optical scattering of the P-polarized incident light. Moreover, this plasmonic mode changes significantly from gap plasmon mode to Fabry–Perot-type resonance in a hBN thickness of 50–90 nm. Our analysis reveals that the proposed hybrid structure based on Ag nanowires and stepped hBN provides a well-defined gap thickness and is a robust platform for analyzing gap plasmon modes.

We report on the development of high-performance transparent conducting GaSnO (GTO)/Ag/GTO multilayer electrodes for display applications. The optical and electrical characteristics of the GTO/Ag/GTO multilayers were investigated as functions of GTO layer (dGTO) and Ag layer (dAg) thicknesses. With increasing dGTO from 10 to 50 nm, the sheet resistance slightly increased from 3.83 to 4.81 Ω/sq, the carrier concentration decreased from 4.76 × 1022 to 1.12 × 1022 cm−3, and the mobility (μ) slightly changed from 10.7 to 10.3 cm2/V. The 40 nm-thick GTO-based multilayer exhibited the mean transmittance (Tav) of 91.6% and had the Haacke's figure of merit (FOM) of 87.84 × 10−3 Ω−1. The μ value increased from 7.97 to 11.67 cm2/V and sheet resistance varied from 7.81 to 3.47 Ω/sq as increasing dAg from 9 to 15 nm. The Tav of the GTO (40 nm)/Ag/GTO (40 nm) samples decreased from 94.5% to 84.9% with increasing dAg. The optical bandgaps of the GTO and GTO/Ag/GTO (40 nm/12 nm/40 nm) films were estimated to be 4.06 and 3.94 eV, respectively. Finite-difference time-domain calculations were conducted to explain the dAg and dGTO dependent transmittance of the GTO/Ag/GTO samples. With the phasor analyses, the dGTO dependence of the transmittance of GTO/Ag (12 nm)/GTO multilayers is described and discussed. Furthermore, the optical and electrical features of the optimal GTO/Ag/GTO (40 nm/12 nm/40 nm) electrode are compared with those of sputter-deposited 92 nm-thick indium tin oxide (ITO) films.

In recent year, vanadium-doped tribological films have become available as possible candidates for self-lubrication at high temperatures. In this work, quaternary Al–Cr–V–N films were deposited onto silicon wafer and WC-Co substrates by an unbalanced magnetron sputtering using high purity (99.99%) CrAl2 and V targets with argon-nitrogen reactive gases. EPMA results revealed that vanadium atoms can incorporated from 0 to 13 at.% into the films. The maximum hardness value was ~32 GPa at vanadium content of 7.1 at.% in the Al–Cr–V–N films. The high-temperature tribometer was used to analysis the friction characteristics of the films with elevated temperature. As a result of the high temperature friction test after heating up to 700 °C, the average friction coefficient decreased from 0.62 to 0.35 with increasing of vanadium contents in the Al–Cr–V–N films. It is concluded that the reduction of the friction coefficient is attributed to the formation of V2O5, which is a Magnéli phase that acts as a lubrication at high temperature.

Abstract A binder-free porous NiCu(CO3)(OH)2 composite was grown on a polyacrylonitrile (PAN) nanofiber substrate using a hydrothermal method. PAN nanofibers were fabricated by the electrospinning method, thus producing a substrate with a nano-sized diameter and high specific surface area. The composite NiCu(CO3)(OH)2 nanowires on PAN nanofibers provided the large specific surface area required for the redox reaction. Transition metal-based nanowires and nano-sized PAN substrates indicate a synergistic effect in electrochemical performance. The NiCu(CO3)(OH)2 on PAN composite showed a remarkable maximum specific capacity of 870 mAh g−1 at a current density of 3 A g−1, which indicates that it can be a suitable electrode material. In addition, an asymmetric supercapacitor with NiCu(CO3)(OH)2 on PAN composite as the cathode and graphene as the anode showed an ultra-high energy density of 89.2 W h kg−1 at a power density of 835 W kg−1 and a capacitance retention of 90.1% after 5000 cycles. Graphic abstract

Layered metal chalcogenides with highly promising thermoelectric properties have attracted attention owing to their intrinsically low thermal conductivity, which originates from their unique layered structure and van der Waals bonding. InSe, a post-transition metal chalcogenide, also has layered atomic structure and low thermal conductivity. We investigate the effects of S doping of Si-doped InSe, In0.9Si0.1Se. The S-doped In0.9Si0.1Se exhibits enhanced thermoelectric properties, with a higher power factor and lower thermal conductivity compared to Si-doped InSe. A significant increase in carrier mobility has an overall positive effect on the electronic transport properties, resulting in a systematic increase in power factor from 0.05 to 0.15 mW/mK2 with S doping. In addition, the thermal conductivity systematically decreases with S doping owing to additional point-defect scattering. Because of the higher power factor and lower thermal conductivity, the thermoelectric figure of merit of the In0.9Si0.1Se0.9S0.1 sample at 735 K was 0.18, which is 3.6 times that of In0.9Si0.1Se.

In this study, tetrahedrite compounds doped with Sn were prepared by mechanical alloying and hot pressing, and their charge transport and thermoelectric properties were analyzed. X-ray diffraction analysis revealed that both the synthetic powders and sintered bodies were synthesized as a single tetrahedrite phase without secondary phases. Densely sintered specimens were obtained with relatively high densities of 99.5%-100.0% of the theoretical density, and the component elements were distributed uniformly. Sn was successfully substituted at the Sb site, and the lattice constant increased from 1.0348 to 1.0364 nm. Positive signs of the Hall and Seebeck coefficients confirmed that the Sn-doped tetrahedrites were p-type semiconductors. The carrier concentration decreased from 1.28 × 1019 to 1.57 × 1018 cm-3 as the Sn content decreased because excess electrons were supplied by doping with Sn4+ at the Sb3+ site of the tetrahedrite. The Seebeck coefficient increased with increasing Sn content, and Cu12Sb3.6Sn0.4S13 exhibited maximum values of 238-270 µVK-1 at temperatures of 323-723 K. However, the electrical conductivity decreased as the amount of Sn doping increased. Thus, Cu12Sb3.9Sn0.1S13 exhibited the highest electrical conductivity of (2.24-2.40) × 104 Sm-1 at temperatures of 323-723 K. A maximum power factor of 0.73 mWm-1K-2 was achieved at 723 K for Cu12Sb3.9Sn0.1S13. Sn substitution reduced both the electronic and lattice thermal conductivities. The lowest thermal conductivity of 0.49-0.60 Wm-1K-1 was obtained at temperatures of 323-723 K for Cu12Sb3.6Sn0.4S13, where the lattice thermal conductivity was dominant at 0.49-0.57 Wm-1K-1. As a result, a maximum dimensionless figure of merit of 0.66 was achieved at 723 K for Cu12Sb3.9Sn0.1S13.

The substitutional solid solution Mn1-xVxP compounds are proposed as a high performance anode for lithium ion batteries (LIBs) through a novel alloying/insertion hybrid electrochemical reaction concept by combining alloying reaction-type MnP and insertion reaction-type VP. The solid solution series of Mn1-xVxP are successfully synthesized via a facile high energy mechanical milling. Their electrochemical properties as an anode for LIBs are systematically studied and compared with those of MnP/VP mixture, particularly focusing on the verification of simultaneous alloying/insertion hybrid electrochemical reaction in the solid solution compounds. The Mn0.75V0.25P solid solution electrode shows the excellent high rate cyclability delivering the reversible capacity of 321 mAh g−1 after 5000 cycles at a high current density of 1.0 A g−1, resulting from the synergistic effects of two reaction mechanisms. The homogeneously substituted vanadium ions enable the alloying/insertion hybrid electrochemical reaction in a Mn1-xVxP single phase, which can effectively reduce the rate of volume change, hinder the pulverization and agglomeration of alloying reaction-type Li-Mn-P crystallite during cycling, and ensure the fast electron and ion transport. This simple, yet innovative, solid solution design with the consideration of structural relationships and electrochemical properties inspires the development of advanced ternary or multi-component compound electrode materials for LIBs or other energy storage devices.

With the ever-growing demand for clean and viable energy sources, the possibility and need to use a multifunctional energy system having integrated energy storage and conversion capacity has been intensified in current times. To fulfill this requirement, a search for an active material having an efficient bifunctional capacity of both hydrogen evolution reaction (HER) and supercapacitor is an essential requirement. The metal polyphosphate with the advantage of abundance, environmental friendliness, low cost, and reliable activity make it an emerging class of novel material for the present research. Herein, for the first time, the comparison of the amorphous and crystalline form of tin polyphosphate-based electrode was assessed toward hydrogen evolution reaction and supercapacitor. Considering the synergistic influence of abundant tin polyphosphate and the three-dimension structure of nickel substrate, we unswervingly deposited well-defined hierarchical in-situ amorphous SnPxOy and ex-situ crystalline SnPxOy over Ni foam using the one-step hydrothermal route. Impressively, amorphous SnPxOy/NF electrode required less over the potential of the only 100 mV with Tafel slope of 50 mV dec−1 to attain a current density of 10 mA cm−2 in comparison to crystalline SnPxOy/NF electrode showing over the potential of the only 170 mV with Tafel slope of 80 mV dec−1 to attain the same current density in 1 M KOH. Additionally, we investigated this electrode in a supercapacitor and found that amorphous SnPxOy/NF delivers a good specific capacitance of 580 F g−1 at a current density of 1 A g−1, greater rate capability, and cyclic stability. Hopefully, this study may demonstrate a promising technique for the preparation of ample, low-cost electrodes for future applications in both HER and supercapacitors applications.

The impact of different parameters on the chemical degradation of the Nafion polymer electrolyte membrane was investigated in detail under different concentrations of Fenton solution. As a consequence of chemical degradation, the performance and durability of the perfluorosulfonic acid-based electrolyte membrane in fuel cells was studied. Quantitative estimation of fluoride emitted after chemical degradation of the electrolyte membrane is done by an ex-situ fluoride emission rate-test using a potentiometric with an ion-selective electrode. The concentration of fluoride ions is easily affected by several external factors, such as total ionic strength, pH, temperature, and stirring speed, which causes many errors while reporting the fluoride concentration. Furthermore, the micromorphology of recast Nafion membranes before and after FER rest was thoroughly examined by scanning electron microscope (SEM) and X-ray photoelectric spectroscopy. Here, we report the influence of several external parameters over total fluoride concentration during the estimation of fluoride concentration for the proper correlation of the rate of chemical degradation in polymer electrolytes. This systematic study is beneficial for removing errors while measuring fluoride concentration and removing the discrepancy present in FER results reported in the literature.

To develop South Korea’s own SFR nuclear fuel cladding tube that has excellent high temperature creep characteristics, candidate alloys for a new cladding material that has better performance than the conventional Gr.92 (9Cr–2W–Nb–V) steel were selected by conducting a high temperature tensile test and creep test for the candidate alloys fabricated by adequately combining precipitation and strengthening of alloy elements (C, Ta, Nb, V, N) with solid solution treatment and hardening of alloy elements (Cr, Mo, W, B). Among the candidate alloys, two types—FC92B and FC92N—that had excellent creep characteristics were used to fabricate the cladding tubes. In the results of the creep test, when a cladding tube was fabricated by using FC92N, which showed excellent creep performance in the air atmosphere, the creep performance declined. After the creep tests of FC92B and FC92N cladding tubes, this study examined the microstructures of specimens and analyzed the relationship between microstructure and creep rupture life. When the creep test was performed in the air and argon gas atmosphere, FC92N showed a larger increase in the thickness of an oxide layer than FC92B. It was determined that the FC92B alloy, in which 130 ppm of B was added, showed excellent creep performance in both the air and argon gas atmospheres because its oxidation resistance was relatively excellent compared to that of FC92N.

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al–Zn–Cu–Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al–Zn–Cu–Mg–xLi alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 µm, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.

We have synthesized a thermally curable polymeric gate insulator (TFVOB-SPI) through the modification of soluble polyimide (SPI) using a 4-(1,2,2-trifluorovinyloxy)benzoyl (TFVOB) chloride. The the...

In this study, microstructure and sintering behaviors of the gas-atomized Al-(25 or 30) Cr–xSi alloy (x = 5, 10 and 20 at.%) during spark plasma sintering (SPS) process were investigated. Gas-atomized alloy powders were manufactured using Ar gas atomizer process. These alloy powders were consolidated using SPS process at different temperature under pressure 60 MPa in vacuum. Microstructures of the gas-atomized powders and sintered alloys were analyzed using scanning electron microscopy (SEM) with energy–dispersive X-ray spectrometer (EDS), and transmission electron microscopy (TEM). Hardness of the SPS sintered alloys was measured using micro Vickers hardness tester. The Al–Cr–Si bulks with high Cr and Si content were produced successfully using SPS sintering process without crack and obtained fully dense specimens close to nearly 100% T. D. (Theoretical Density). The maximum values of the hardness were 834 Hv for the sintered specimen of the gas atomized Al–30Cr–20Si alloy. Enhancement of hardness value was resulted from the formation of the multi-intermetallic compound with the hard and thermally stable phases and fine microstructure by the addition of high Cr and Si.

To understand the mechanism of ring shakes in Dahurian larch (Larix gmelinii), the ring shake surface on the tangential section was observed and compared with the shear surface of green and air-dry wood. Macroscopically, the ring shakes occurred in the heartwood between the 20th and 40th growth ring. The ring shake surface exhibited an even and clean structure without the fluff. The shear surface of the green wood showed a larger amount of fluff compared to that of air-dry wood. In microscopy, ring shake failure occurred at the end of the latewood and/or the beginning of earlywood or within the earlywood zone. The ring shake surface was covered with a resinous substance, and the wood cells were observed after removing the resinous substance with ethanol. The tracheid walls in the ring shake and shear surface of green wood primarily exhibited intercell failure and rarely intrawall and transwall failures. In air-dry wood, the tracheid walls in the shear surface mostly exhibited intrawall and transwall failures. In the ring shake surface, there was hardly any failure in the epithelial and ray cells, thereby showing a distinct difference compared to the shear surface of the green and air-dry woods.