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Recently, oxide-based materials have proven to be potential thermoelectric materials at high temperatures. In this work, the thermoelectric properties of one-step solid-state sintered Sn1-xSbxO2 (x = 0, 0.005, 0.01, 0.02, 0.03, 0.04) ceramic pellets were investigated in detail. It was confirmed that the addition of Sb significantly alters the thermoelectric properties of SnO2 due to the increase in the carrier concentration, which increases the electrical conductivity. The Seebeck coefficient values of all the solid solutions were negative, which indicates that these samples have n-type conduction. The thermoelectric performance of the material was evaluated by determining the zT value and the best composition was Sn0·98Sb0·02O2 with zT ∼0.06 at 1073 K.

This manuscript comes up with a unique GaAs-filled elliptical core-based hexagonal cladding PCF that manifests ultra-high birefringence (Br) and non-linear coefficient (NLC). The distinct optical characteristics of the PCF are thoroughly simulated and analyzed by the finite element method (FEM) through the commonly available COMSOL Multiphysics software. The simulated findings confirm that using the high refractive index (RI) advantages of GaAs at the effective wavelength of 1.55 μ m , a high Br of 0.92 , as well as an ultra-high NLC of 2.06 × 10 6 W − 1 K m − 1 and zero-dispersion can be obtained. Besides, several primary optical properties, namely numerical aperture (NA), confinement loss (CL), power fraction (PF), dispersion, etc. are also discussed and investigated in depth in the propounded article. The zero-dispersion characteristic, as well as the high Br and ultra-high NLC of the advanced PCF model, make it a worthy candidate for extensive purposes, including biochemical detection, high nonlinear applications, supercontinuum generation, optical communication and other sensing applications.

In this work, a commercial 3 mol% yttrium oxide partially stabilized zirconia spray-dried granules were used as such, and after intensive milling, for the production of dense samples by robocasting technique. The aim was to evaluate the suitability of using spray-dried granules instead of submicron particles in robocasting of ceramic parts. To this aim, robocasting pastes were produced from the as-received granules as well as from nanometric particles obtained from an effective ball milling of the granules. The formulation of the pastes was optimized in order to achieve optimal printability. The drying conditions were optimized as well, and the control of temperature and humidity either in the printing and drying chambers allowed to eliminate any warping issue. After sintering at 1450 °C, the monolithic dense parts were characterized by ultra-fine and highly sintered microstructures, with the highest density achieved by the sample produced from granules. This material not only did not show the typical defects of granules-derived ceramics but was also characterized by fewer and smaller defects than the sample produced by the fine particles. It seemed that the presence of large granules, and thus large intergranular space, favored the debinding process and limited the formation of the typical processing flaws. The ball-on-three balls test was used for the evaluation of the mechanical properties of the dense samples. Biaxial flexural strength values in the range from ∼100 to 500 MPa (with an average value of 255 ± 93 MPa) were determined for the samples made from granules while these values ranged from ∼100 to 300 MPa (with an average strength of 198 ± 52 MPa) for the samples prepared from the milled particles. In spite of low, these values are in line with literature data, obtained on 3 mol% Y2O3–ZrO2 samples fabricated by the robocasting technique, and suitable to demonstrate the feasibility to use as-received granules as feeding material for robocasting parts.

International audience; Shards of Blue-and-White Ming porcelain from shipwrecks of Portuguese ships found on the coasts of South Africa plus a shard from Mombasa (Kenya) were analyzed by optical microscopy, SEM-EDS and Raman microspectroscopy (458 nm). Whereas the Raman signature of porcelain body paste compositions which are based on mullite, quartz and an amorphous phase with the minor presence of anatase and feldspar are very comparable whatever the variable alumina content, at least two types of glazes are observed: a high-temperature soda-potassium glaze, and glazes richer in calcium and similar to a celadon glaze (with the possibility of wollastonite formation). The blue decoration is obtained with a material rich in manganese typical of the Ming productions. Some shards exhibit a two-layer glaze and the blue decoration is either placed under-glaze, or in-glaze as found in the Vietnamese productions of the same period. Previous assignments of the Raman signature of feldspar to cobalt aluminate are now not favoured (blue colour is obtained with Co2+ ions dissolved in the glassy silicate) and several black spots exhibit the characteristic spectrum of an epsilon Fe2O3 phase being present.

Natural spinal tissues have unique dynamic properties and it is crucial to investigate the full dynamic response of spinal implants and related biomedical materials to ensure compatibility with the host tissue. Silicon nitride is a promising bioceramic for spinal implants. In this study, the mechanical properties and dynamic response of silicon nitride were comprehensively evaluated using novel and efficient testing methods, at both the material and structural level. The correlation between mechanical properties and porosity was investigated and the results showed that Young's modulus and compressive strength decreased non-linearly as porosity increased. Both the compressive strength (100.35±3.39MPa) and fracture toughness (1.06±0.06MPa⋅m1/2) of the porous silicon nitride samples (~70% porosity) can be considered sufficient for load bearing purposes as a substitute for trabecular bone. Moreover, the results from a drop tower test showed that the average ultimate strength of the scaffolds under an impact loading was significantly lower than the strength under quasi-static compression. Nevertheless, this value is still comparable to that of trabecular bone. Regarding damping capacity, the results of free damped vibration tests of cantilever beams showed that a silicon nitride beam has a higher damping ratio (0.17%±0.01%) than a zirconia beam (0.13%±0.01%), which indicates that ceramics with similar Young's moduli can have different energy dissipating capacities. However, both dense and porous silicon nitride showed a low energy dissipation, substantially lower than natural spinal tissues. Overall, dense silicon nitride possesses a high stiffness, and altering the porosity of silicon nitride is one option to tailor its mechanical properties towards those of trabecular bone, however, more effort is required to increase its damping capacity, if this is a desired trait., Ceramics International, 47 (23), ISSN:0272-8842, ISSN:1873-3956

Si3N4–SiC/SiO2 composites were prepared by employing three-dimensional (3D) printing using selective laser sintering (SLS) and infiltration processing. The process was based on the infiltration of silica sol into porous SLS parts, and silicon carbide and silicon nitride particles were bonded by melted nano-sized silica particles. To optimize the manufacturing process, the phase compositions, microstructures, porosities, and flexural strengths of the Si3N4–SiC/SiO2 composites prepared at different heat-treatment temperatures and infiltration times were compared. Furthermore, the effects of the SiC mass fraction and the addition of Al2O3 and mullite fibers on the properties of the Si3N4–SiC/SiO2 composites were investigated. After repeated infiltration and heat treatment, the flexural strength of the 3D-printed Si3N4–SiC/SiO2 composite increased significantly to 76.48 MPa. Thus, a Si3N4–SiC/SiO2 composite part with a complex structure was successfully manufactured by SLS and infiltration processes.

Steel materials employed in severe conditions including strong corrosion, high load and multi-factor coupling damages can easily cause incredible degradation until failure, and the protective CrN-based coatings should be one of promising candidates to relieve those damages for the steel equipment or components. In present paper, the monolayer CrAlN and multilayer Cr/CrAlN coatings were successfully deposited on steel substrates by multi-arc ion technology, and their microstructure, mechanical, tribological and corrosion performances were systematically investigated. The results show that the special multilayer Cr/CrAlN coating could possess much better load-bearing capacity and wear resistance than that of monolayer CrAlN coating, which was due to the facts that the multilayer architecture can effectively release the internal stress and inhibit the expansion of defects. Particularly, the multilayer interfaces could effectively prevent the aggressive medium in seawater infiltrating into the inside of coating, and thus the multilayer Cr/CrAlN coating could have higher corrosion resistance compared to monolayer CrAlN coating. As a result, this multilayer Cr/CrAlN coating could achieve excellent combined performances, indicating that it has greatly potential application as protective coating in seawater.

Layered O3 type oxides exhibit promising prospects as high-performance cathodes for sodium-ion batteries (SIBs) due to their low cost and high theoretical capacities. Nevertheless, the intrinsic surface composition and bulk structure degradation upon cycling presents a huge obstacle to stable sodium-ion storage/transportation. Besides, the effective surface decoration on layered O3 oxides is still challenging through conventional wet chemical route owing to their extraordinarily high surface sensitivities. Herein, a typical O3 type layered oxide of NaNi0.5Mn0.5O2 (NNMO) was selected and successfully encapsulated by precisely controlled Al2O3 layers via atomic layer deposition (ALD) technology. With the optimally controlled Al2O3 thickness of 3 nm, the surface regulated NNMO delivers a highly reversible capacity of 73.6 mA h g-1, with a significantly improved capacity retention of 68.0% after 300 cycles at 0.5 C, and a superior rate capability of 65.8 mA h g-1 at 10 C. Further air sensitivity tests demonstrate that the protective layer could effectively mitigate the generation of sodium-based impurities on NNMO, and reduce the surface sensitivities. Both chemical and electrochemical aging tests confirm the contribution of Al2O3 coating layer in alleviating ion dissolution as well as stabilizing the structure and morphology of NNMO. Based on regulating the surface of O3 type layered oxides utilizing ALD technique, this work supplies an effective and facile strategy to overcome the challenges from fast structure degradation and electrochemical property decay, which not only highlights the significance and effectiveness of surface engineering in secondary batteries, but also sheds light on accurate interface construction and regulation for active electrode materials, particularly for those sensitive to ambient atmosphere.

Chalcohalide glasses with a gradient refractive index (GRIN) microstructure were imprinted by microthermal poling for realizing diffractive optical elements covering the visible to middle-infrared wavelength range. The effect of halogen ions on the saturation poling voltage (U), surface profile, diffraction pattern, optical transmittance, GRIN microstructure, and structural rearrangement of poled glass is investigated. An effective imprinting formation region for a GRIN microstructure based on the U and glass composition is observed under fixed poling time and temperature. The onset U (60 V–150 V) and activation energy of mobile cations (0.449 eV–0.533 eV) decreases with the atomic number of the halogen from F to I, but the saturation diffractive order (8th to 11th levels) and phase difference (~0.08λ to 0.18λ) increases accordingly. The onset U and activation energy decrease with the deformability of the glass network and radius of the halogen ions. The phase difference and saturation diffractive orders decrease with the proportion and electronegativity of interval halogen atoms in the glass network. Thus, chalcohalide glasses with GRIN microstructures can be tailored by adjusting the type of halogen ions for realizing various diffraction optical elements.

The precision fabrication of ceramic moulds for the mass-production of micro/meso-structural arrays places a tremendous challenge to the manufacturing industry. This work aims to reveal the physics behind the processes so as to address this technological challenge. A new method for texturing the diamond grinding wheel surface with a micro-abrasive waterjet is proposed for highly efficient form-grinding of ceramic moulds into the required micro/meso-structural surfaces. It shows that this technology provides some unique advantages in improving the sharpness and geometrical accuracy of the grinding wheels. The mechanisms about material removal and texture formation in grinding wheel truing are investigated to enable the precise control of micro/meso-structure generation on the grinding wheel. A theoretical model is established to study the effect of grinding wheel surface micro/meso-textures and grain trajectory on the quality of the ground mould surface and reveal the reflection mechanism of the ground marks on the mould surface. Furthermore, an integrated rough-fine grinding strategy is proposed which is shown to significantly increase the grinding efficiency by 15–24 times. It is found that ductile domain grinding of ceramic moulds to achieve the required contour profile of 6.7 μm PV accuracy and a surface roughness Ra of less than 40 nm can be achieved.

Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al2O3), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al2O3 was activated by oxalic acid. XRD, 27Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al2O3 decreased to 1029 °C for oxalic acid activated γ-Al2O3, and the α-fraction was 100% for activated γ-Al2O3 at 1300 °C. After oxalic acid activation, the diffraction peak intensity of γ-Al2O3 decreased significantly; the results of 27Al-MAS-NMR suggested that octahedral [AlO6] in γ-Al2O3 was easier than tetrahedral [AlO4] to be attacked by oxalic acid, and the formation of pentavalent [AlO5] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al2O3. The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al2O3 and extracted Al as three complexes of [Al(C2O4)]+, [Al(C2O4)2]- and [Al(C2O4)3]3-. Oxalic acid activated γ - Al2O3 with a lower phase transformation temperature has broad application prospects in the alumina industry.

Grain boundaries typically dominate the electrical properties of polycrystalline ceramics. To understand the effect of grain boundaries on the electrical conductivity of SiC ceramics sintered with 2000 ppm Y2O3, the electrical resistivity of individual grains and multi-grains across boundaries at the micron scale was measured using a nano-probing system equipped with nano-manipulators. The results revealed that grain resistivity was bimodal because of the existence of a core/rim structure in grains, and the electrical resistivity of multigrain samples slowly increased with an increase in the number of grain boundaries crossed. Specifically, the electrical resistivity of a grain without a core, a grain with a core, a bicrystal with a single boundary, a sample crossing three boundaries, and a bulk polycrystalline sample were 2.36 × 10-1, 5.05 × 10-1, 4.80 × 10-1, 5.04 × 10-1, and 5.84 × 10-1 Ω cm, respectively. The results suggest that the electrical resistivity of polycrystalline SiC ceramics is primarily influenced by the presence of a grain boundary or core and secondarily by the number of boundaries.

Semiconductor-metal heterostructure, especially represented by various inorganic semiconductors-platinum (Pt) hybrids, is widely applied in converting solar power to chemical energy. Given the scarcity of Pt and the availability of coupling, the development of a non-Pt regimen and facile assembly strategy is critical. In this study, CdxZn1-xS/Ti3C2 ultrathin MXene composites were availably prepared with a facile electrostatic assembly strategy. The unique 0D/2D assembly demonstrated remarkably enhanced performance toward photocatalytic hydrogen production compared with bare CdxZn1-xS. Spectroscopic characterization analysis and band theory discussion substantiated the effects of electronic interaction and the Schottky barrier arising from intimate contact of CdxZn1-xS and Ti3C2 MXene on the swift separation of photoinduced electron-hole pairs. Successful application of electrostatic self-assembled CdxZn1-xS with ultrathin MXene opens a new area of utilizing electrical difference and band theory to prepare rational semiconductor/MXene Schottky structure towards various photocatalytic reactions.

In this work, a method combining the spray-drying process and rolling ball method was first selected to mass fabricate Li2TiO3 tritium breeder ceramic pebbles. Herein, we overcome the issues namely complex production, high manufacturing cost, and lower mechanical strength in previous reports. The Li2TiO3 powder with high packing density after the spray drying process will self-agglomerate to form denser structured pebbles during the rolling ball process assisted by sesbania gum binder solution. The stability of slurry, different binder, binder concentrations, the formation mechanism, and the morphology of green pebbles were investigated by using viscometer, SEM. Moreover, the force on the Li2TiO3 green pebbles was also analyzed during the rolling ball process. After the debinding and densification process, the Li2TiO3 pebbles have a uniform diameter of 1.2 mm and good sphericity of 0.97. The Micro-CT instrument showed that the internal structure of the Li2TiO3 pebbles was dense. The experiment's confirmation shows that the Li2TiO3 ceramic pebbles sintered at 1000 °C have optimal mechanical properties such as a crushing load of 108 N and relative density of 92.4%TD, which is much larger than that of the pebbles obtained using traditional methods. This work not only overcomes the core-shell structure but also provides a new platform for better mechanical properties for studying the other materials systems in the future.

A simple hydrothermal method was used to prepare palladium-doped few-layer molybdenum disulfide nanosheets grown on the surface of a multi-walled carbon nanotube (Pd–MoS2/CNT) with forming a three-dimensional (3D) hierarchical core-shell heterostructure. This paper provides first-hand information on electromagnetic interference (EMI) scattering and electromagnetic (EM) parameters in the X-band (8–12 GHz) microwave frequency range. In this hierarchical core-shell heterostructure, SEM and TEM photos clearly show that CNT forms the core, while Pd-doped few layers MoS2 grown on the surface of CNT is the shell. The Pd-doped MoS2/CNT nanohybrids can greatly improve electrical conductivity, defect dipole polarization, interfacial polarization, dielectric relaxation loss, and mobile charge carriers between core and shell. These are the reason for the substantial enrichment in EMI shielding effectiveness (SE) and dielectric performance. The 10% Pd–MoS2/CNT nanohybrid has a higher EMI SE and dielectric loss tangent (SET ~ 26.50 dB, tan δ e ~2.37) than the 5% Pd–MoS2/CNT (SET ~ 22.50 dB, tan δ e ~1.90) and undoped MoS2/CNT (SET ~ 21.55 dB, tan δ e ~0.92) at the same thickness of 1 mm. The strong EMI SE and dielectric loss tangent are found due to their higher dipole polarization, conduction, and relaxation losses. The doping concentration of Pd-atoms has a significant impact on EM parameters (e′, e″, μ′ & μ″) and EMI scattering parameters (S11, S21, S12 & S22). The experimental results indicated that the 10% Pd–MoS2/CNT nanohybrid might be considered a good EMI shielding and dielectric material for large scale use in intelligence wireless information and communication devices in the future.

This study presents a method for synthesizing hydroxyapatite (HA) with high crystallinity at low temperatures using a small amount of graphene oxide (GO), and the characters of produced GO/crystalline HA complex was investigated. The morphology and components of the synthesized HA (i.e., HA/GO) were analyzed through scanning electron microscopy, X-ray diffraction and transmission electron microscopy; additionally, the yield of the HA/GO was assessed. The HA/GO results were analyzed by comparing them with those obtained using HA synthesized without GO as a control group. A yield of ~4 mg of HA/GO was attained by the use of 100 μg of GO, demonstrating 20% improvement over the control group. The crystal phase analysis confirmed that crystalline HA of fine quality with nano-size was simply synthesized without intermediate phases using adding a small amount of GO, and the synthesized HA without GO is consist of intermediate phases (brushite and octacalcium phosphate) and hydroxyapatite. Biological characteristics of HA/GO were assessed through the behavioral analysis of mesenchymal stem cell attachment, proliferation, differentiation, and its protein adhesion capacity. HA/GO exhibited excellent biocompatibility and osteogenic differentiation behavior together with better protein adhesion ability than HA. These results demonstrate potential of HA/GO for application in bone tissue engineering. Thus, HA/GO can be developed as a biomimic biocomposite by combining it with bioactive molecules such as growth factors.

MXenes are two-dimensional materials that can be used in various fields due to their large surface areas, electronic possessions, high mechanical strength, hydrophilicity, and antibacterial properties. First, a summary of the structure and properties of MXenes is presented in this review. Efforts for delamination or exfoliation of MXene sheets are introduced. Because little research works have focused on the different roles of MXenes-based materials in tackling environmental pollution, this review concentrates on the importance of MXenes and their hybrids in eliminating environmental pollution, especially water. As can be seen in the following, MXene can help in various forms of membrane, absorbent, catalyst, and as a shield to eliminate environmental pollution. To build a basic understanding of remediation processes, the mechanism of pollutant removal in adsorption, degradation, and other remediation manners is discussed in detail.

A series of xPbO–(45-x)CuO–55B2O3 glasses (5 ≤ x ≥ 40 mol %) were prepared by the melt-quenching technique. The X-ray diffraction (XRD) patterns of the prepared glasses are found to have amorphous structure. An extensive ultrasonic study has been made to explore the structural role of PbO and CuO in the borate network. Various elastic properties were calculated from the measured data of density and ultrasonic velocity. Ultrasonic velocity and elastic moduli revealed broad humps at about 20 mol % PbO, which are attributed to the borate anomaly. Below 20 mol % PbO, all Pb2+ ions are considered to be entering the borate network as a glass modifier. This results in the transforms the borate network from an open structure to a denser three-dimensional structure due to BO3 → BO4 conversion. Beyond 20 mol, addition of PbO results in the formation of metaborate, pyroborate, and orthoborate units with NBOs. This weakness the glass structure and decrease both ultrasonic velocity and elastic moduli. The elastic properties were predicted and quantitatively analyzed by taking into account the effect of boron coordination number on the compositional and structural parameters involved in Makishima–Mackenzie's theory, ring deformation model and bond compression model. An excellent agreement between the computed theoretical and experimental elastic moduli, micro-harness and Poisson's ratio was achieved for majority of samples.

Titanium nitride (TiN) is widely used in electrode materials in fast charging/discharging supercapacitors (SCs) due to its outstanding conductivity. However, the low capacitance of the TiN electrode limits its further application in the SCs. Therefore, the reasonable design of the TiN electrode with high electrochemical and mechanical properties is still a challenge. In this paper, the silicon nanowires/titanium nitride electrode (Si NWs/TiN) is prepared by depositing TiN onto the etched Si nanowires by direct current magnetron sputtering. The Si NWs are prepared by etching silicon in 4.8 M HF/0.02 M AgNO3 aqueous solution for different times (5 min, 15 min, 30 min, 60 min). The mechanism of the effect of etched silicon substrate morphology on the electrochemical performance of Si NWs/TiN electrode was studied. As the etching time increases, the differences of the TiN surface structure, lattice defects and surface chemical composition will change the capacitance performance and charge storage mechanism of the Si NWs/TiN electrode. The prepared Si30 NWs/TiN electrode exhibits an outstanding specific capacitance as high as 113.55 F g−1 at a scan rate of 5 mV s−1 with 0.5 M H2SO4 solution as electrolyte. The specific capacitance of the Si30 NWs/TiN electrode is as high as 7.5 times that of the electrode without etching at 100 mV s−1. The Si30 NWs/TiN electrode has an excellent cyclic stability performance, which the electrode has a decay rate of 12.4% after 2000 cycles. This indicates that the electrode has reliable stability. The electrode of the supercapacitor prepared by this method can open up a new way to expand the specific surface area of other transition metal nitride.

A series of novel Ba1-xAl2Si3O4N4: xYb2+ yellow-emissive long-afterglow phosphors was successfully synthesized via a high-temperature solid-state reaction with two sintering steps. The phosphors exhibited broad band emission (full width at half maximum, FWHM = 107 nm) with a peak at 518 nm. With an increase in the Yb2+ doping content in Ba1-xAl2Si3O4N4: xYb2+ phosphors, the luminescence intensity reached a maximum at x = 0.15. The long-afterglow phosphor can be activated effectively by 254 nm UV light, and the afterglow can persist for more than 7 h. From the thermoluminescence (TL) spectrum, there are three types of electron traps, with average evaluation depths of 0.485, 0.592, and 0.681 eV. The afterglow is caused by the capture and re-release of free electrons by the three trap energy levels. Finally, the thermal and chemical stability of the phosphor was tested, its luminescence intensity was 78.7% at 150 °C and 99.5% after 5 h soak in water compared to that at room temperature and original, respectively.

Industrial spent MoSi2-based materials and HfO2 were recycled as raw materials to fabricate MoSi2-HfO2 composite coating by spark plasma sintering (SPS). The microstructural evolution of the coatings was characterized and the 1500 °C oxidation behavior was explored. Cracks penetrated through the MoSi2 coating while no cracks can be found in the HfO2-containing composite coating owing to the reduction of the mismatch of thermal expansion coefficient (CTE). Good metallurgical bonding was exhibited since (Mo,Nb)5Si3 diffusion layer was found in the HfO2-containing coating by the diffusion of Nb and Si across the interface without gaps. After 1500 °C oxidation of 20 h, cracks appeared in the surface of SiO2 layer on MoSi2 coating while the HfO2-containing composite coating possessed crack-free oxide scale. HfSiO4 with high temperature (>2900 °C) is formed during oxidation and it inlays in the silica oxide scale to improve the stability. Compared to MoSi2 coating, Nb coated MoSi2-HfO2 has thinner oxide scale with lower mass gain during oxidation, thus presenting better high-temperature anti-oxidation properties.

The present work reports a comparative study of synthesis process-dependent physicochemical, optical, electrical, and photodetective properties of earth-abundant quaternary Cu2FeSnS4 (CFTS) nanoparticle-based films. CFTS nanoparticles are synthesized via solvothermal and monoethanolamine-assisted hydrothermal processes. X-ray diffraction (XRD) and Raman spectroscopy analyses confirm the phase purity of the synthesized particles. FE-TEM, FE-SEM, and energy-dispersive X-ray spectroscopy (EDS) results demonstrate the formation of smaller particles (~5–10 nm) with stoichiometric chemical composition and larger particles (~100 nm) with Cu-deficient chemical composition in hydrothermal and solvothermal processes, respectively. The optical bandgaps of the hydrothermal and solvothermal-processed CFTS nanocrystalline-based films are calculated to be 1.56 and 1.48 eV, respectively. The temperature-dependent electrical properties of the CFTS nanocrystalline films are analyzed by the transfer length method. The electrical conductivity of hydrothermally and solvothermally synthesized CFTS nanoparticle-based films increased from 31.02 ± 4.04 and 3.12 ± 0.69 mS/cm to 67.73 ± 5.84 and 17.62 ± 2.62 mS/cm, respectively, with an increase in the measuring temperature from 298 to 373 K. The temperature-dependent charge transport properties are attributed to the thermal activation of defects in the CFTS films. The hydrothermally synthesized CFTS nanoparticle-based visible photodetectors exhibited photoinactive properties. The solvothermally synthesized CFTS nanoparticle-based devices exhibited maximum photosensitivity of (21 ± 4) %, photoresponsivity of 128 ± 6 mA/W, and detectivity of 4.68 ± 0.86 × 109 Jones. The present study shows that the synthesis process significantly affects the morphology, chemical composition, optical properties, electrical properties, and performance of CFTS nanoparticle-based visible photodetectors.

In this study, GdBa2Cu3O7−ẟ (GdBCO) sol with ultraviolet (UV) sensitivity was prepared using Gd(OAC)3, Ba(OAC)2, and Cu(OAC)2 as the starting materials, methanol as the solvent, and 2,2′-bipyridine as the chemical modifier. Furthermore, chelation mechanism of the chemical modifier and metal ions in the sol was analyzed by infrared and UV absorption spectroscopy. Cu2+ in the sol was found to chelate with the chemical modifier to form a photosensitive chelate, rendering UV sensitivity to the sol. Next, the photosensitive chelate was decomposed by exposing it to UV light, and the decomposition product was barely soluble in organic solvents. By exploiting the self-sensitivity of GdBCO, fine patterns of its films were obtained (without photoresist throughout) with micron scale resolution. XRD and superconductivity performance tests revealed that compared to the GdBCO film without fine patterns, fine-patterned GdBCO fabricated herein does not exhibit significant degradation in terms of its crystal structure and superconductivity. This result indicates that fine-pattern technology developed for chemical film formation is simple in terms of process and equipment, and it does not affect the performance of the GdBCO film. Therefore, “chemically modified self-photosensitive” photolithography can be applied for the preparation of the GdBCO-based inorganic microstructure, which exhibits specific significance for the research and application of high-temperature superconductor electronic devices. In addition, during heat treatment, the technology of first introducing carbon dioxide and then water vapor also was adopted in this paper, which reduced the surface roughness of the GdBCO film.

In this paper, 3 mol% yttria-doped tetragonal zirconia polycrystal material (3 mol% Y2O3–ZrO2) was prepared using an optimised pressureless sintering process. The phase change and particle size distribution of Y2O3–ZrO2 during sintering were studied, and the effect of sintering temperature on the properties of Y2O3–ZrO2 was analysed. The raw materials and prepared samples were analysed using XRD, Raman spectroscopy, SEM, and Gaussian mathematical fitting. The results show that sintering encourages the transformation of the monoclinic phase into the tetragonal phase, thus improving the crystallinity of the sample. The relative content of the tetragonal phase in the sample increased from 57.43% to 99.80% after sintering at 1200 °C for 1 h. In the range of sintering temperatures studied in this paper (800–1200 °C), the zirconia material sintered at 1000 °C presented the lowest porosity and the best density.

Doped PbPdO2 materials have attracted much attention as a spin gapless semiconductor (SGS) with the important properties of colossal electroresistance (CER) and giant magnetoresistance (GMR). In this study, the PbPdO2 thin films with (002) preferred orientation were prepared by pulsed laser deposition (PLD), and the temperature dependences of resistance and resistivity, R (T) and ρI (T), were measured under different applied DC currents. Remarkably, a positive CER effect induced by the current was firstly observed in the PbPdO2 films. In particular, it is novelty found that the positive CER value of PbPdO2 with I = 10 μA and T = 10 K reached about 300%. Moreover, the cyclic ρI (T) curves were also measured for I = 0.01 and 10 μA going back and forth between 10 K and 400 K. The time dependences of ρt/ρ0 ratio with T = 100 K, 300 K, 400 K and I = 0.01 and 0.1 μA were also obtained. A critical temperature Tc with about T = 260 K for all applied currents was found. As T > Tc，the band gap of the film is enhanced by the combined effect of the temperature and current. At the same time, Pb and O vacancies, and the evolution of oxygen valence states in the PbPdO2 film were observed by energy dispersive spectrometer (EDS), electron paramagnetic resonance (EPR) and in-situ x-ray photoelectron spectroscopy (XPS). Especially, the charge transport between O1− and O2− was confirmed by in-situ XPS. Finally, based on first-principles calculation, an internal electric field model and its induced potential barrier were established, which well explains the positive CER effect and the critical temperature Tc.

We present a study on the structural and phonon properties of cobalt-doped orthorhombic molybdenum trioxide (α-MoO3:xCo) hierarchical microrods. The samples were synthesized by solid-state reaction with molar concentrations of 0%, 1%, 3%, and, 5% cobalt. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and Fourier transformed infrared spectroscopy (FTIR) were used to confirm the orthorhombic phase and the structural properties of each sample. The infrared and Raman spectra of the samples show that doping alters the ratio of relative intensities, linewidth, and the shift of the wavenumber of the modes, and a correlation is established between the stretching force constant and wavenumber. Experimental temperature-dependent Raman scattering studies were performed on samples of α-MoO3:xCo over a temperature range of 298–813 K. The Raman spectra showed a phase transition at around 373 K to a self-similar structure, indicating a possible isostructural phase transition (IPT) for samples with 0% and 1% cobalt, a phenomenon rarely reported in the literature. Nevertheless, this phase transition was not observed for samples containing 3% and 5% cobalt, indicating an increase in material stability.

The development of lithium-sulfur batteries (LSB) was hindered due to the shuttling of Li-polysulfides in electrolytes and sluggish electrochemical kinetics of polysulfides. To address these stumbling blocks, we introduced La2O3 nanorods modification of ketjen black@sulfur (La2O3/KB@S) composite that adsorbs and provides sufficient sites with Li-polysufides interaction. The La2O3 nanorods play a key role in the adsorption and catalysis performance of the polysulfides, which further accelerate the redox kinetics. Consequently, the La2O3/KB@S cathode with sulfur loading of 3.1 mg cm−2 attained a high initial discharge capacity of 833 mAh g−1 at a 0.5C rate and displayed excellent cyclic stability with reversible capacity of 380 mAh g−1 after 500 cycles with an average of 98% coulombic efficiency. Further, even with high sulfur loading of 5 mg cm−2, the La2O3/KB@S cathode also presents a capacity of 4.9 mAh at 0.3C and still maintains a stable value of 3.87 mAh after 150 cycles. The results suggest the multifunction La2O3 nanorods anchoring effectively and catalyzing are beneficial to realize the goal of the large-scale application with high load active materials and high-performance LSB.

Long-sized rods of Al2O3–SiC–TiB2 ceramic composite material were obtained by SHS-extrusion. The material was synthesized by self-propagating high-temperature synthesis (SHS) followed by high-temperature shear deformation. Ceramic samples app up to 465 mm in length and 5 mm in diameter were obtained. According to the results of XRD and SEM the obtained rods have a composite structure. The matrix is Al2O3 with distributed titanium diboride and silicon carbide particles. A uniform phase distribution was observed along the entire length of the rod. The microhardness of the matrix was 25–26 GPa, that of the dispersion-strengthening phases - 32–34 GPa. Heat resistance tests showed that during heat treatment at T = 1000 °C for 21 h, the sample specific weight gain and its real rate were 8.3 g/m2 and 1 g/(m2∙h), respectively. The density, hardness and electrical resistivity of the samples obtained in this work were 3.27 g/cm3, 19.5 GPa, 3.1∙10−5 Ohm∙m, respectively.

In the present work, plasma electrolytic oxidation (PEO) is creatively introduced as a novel method to fabricate multi-layered nanospheres. Titanium (Ti) was oxidized in a phosphate-based electrolyte containing ZnO nanoparticles (NPs), which results in the formation of nanospheres on the ceramic coating. The as-fabricated nanosphere is amorphous with a three-layered architecture. The inner layer of the nanosphere contains Zn, Ca and P whereas Cu and P were detected in the medium layer with the outer layer enriched in Cu, O and Ti, which is promising in the field of bio-medical implanted devices. Herein, a novel one-pot synthesis strategy is proposed to fabricate multi-layered nanospheres, which could enlighten the preparation of hierarchical structures in various fields.

Vanadium carbide (VC) as excellent ceramic and functional material is usually prepared by carbothermal reduction of V2O5 which must be extracted from a typical V slag by complex processes. Pollutants, such as ammonia-nitrogen wastewater, NH3 and CO2 are inevitably discharged. A novel and green method for VC preparation was proposed by one-step co-electrolysis of soluble NaVO3 and CO2 in molten salt. It was found that VC with high purity was easily obtained by reducing electrolysis temperature and CO2 flow rate to 600 °C and 10 mL min−1 at 3.0 V. Besides VC with particles and layered stacking structure in products, a small amount of carbon and oxygen elements existed. The atomic percentage contents of C, V, and O elements in VC were about 50.0%, 44.5% and 3.8%, respectively. During electrolysis, CO32− and VO3− was reduced at about −0.55 V (vs. Ag/AgCl) and −1.38 V (vs. Ag/AgCl), respectively. CO32− ions were more easily reduced than VO3−, and was firstly reduced to CO22− and then converted to C. Then, VC was prepared by two routes from CO2 and NaVO3. One route is that VO3− ions are firstly electroreduced to VO2− ions and then are further electroreduced to VC with C. Another route is that VO3− ions are electroreduced to V which in-situ reacted with C to VC. Both VO3− and CO32− ions are electroreduced by two-step process. In final, VC is in-situ deposited on cathode. It provides a novel and green way to prepare VC and also achieves the high value-added utilization of vanadium slag and CO2.

Lithium titanium oxide (Li2TiO3) tritium breeder ceramic plates with nano- and coarse-grain size were fabricated. The preparation methods contained CTAB-modifying precursor, combining dry-pressing with isostatically cold-pressing, and calcinating at optimized sintering temperature in turn. Then their properties were characterized after radiation by 280 keV helium (He+) ion. Extensive characterization analyses were performed to reveal the changes in nano-grained and coarse-grained Li2TiO3 after radiation. They contained glancing angle X-ray diffraction (GIXRD), atomic force microscopy (AFM), electron spin resonance (ESR), and scanning electron microscopy (SEM). The results showed as follows, GIXRD peak position of the nano-grained Li2TiO3 was more stable than the coarse-grained Li2TiO3 after radiation. Nano-grained Li2TiO3 was less rough and swollen than the coarse-grained one after radiation. Nano-grained Li2TiO3 had more excellent structural stability and less defect concentration of Eʹ-center after radiation. As a result, nano-grained Li2TiO3 might have much better radiation tolerance than the coarse-grained one by comparing characterization results.

Composition and structural design play a very influential role in the microwave absorption (MA) manipulation of ferrite/carbon composites. Here, by carefully choosing the dimensionality of the bio-carbon materials, the interfacial geometries and MA properties of ferrite/bio-carbon composites have been controlled effectively. The one dimensional (1D), two dimensional (2D), and three dimensional (3D) biomass-based carbon materials decorated with ZnFe2O4 (ZFO) particles were obtained respectively from carbon fibers (1D), tree leaves (2D), wheat straw (2D), peanut shell (3D) and orange peel (3D) by a simple two-step synthesis method. With increasing the bio-carbon's dimensionality from 1D, 2D to 3D, the ferrite/carbon composite's MA properties are promoted and the minimum reflection loss is enhanced from −9 dB to −45 dB. By changing the ZFO/3D-bio-carbon samples' thickness, a broad absorption range from 4 to 18 GHz can be covered. Moreover, the effective absorption bandwidth for ZFO/3D-bio-carbon can be modified up to 7.1 GHz, which covers the whole Ku band. These observations identified the important roles of the ferrite/carbon interface and dimensionality of carbon materials and provided an effective and low-cost route to design microwave absorption materials based on biomass-industrial waste composites.

In order to use sulfide all-solid-state batteries as power sources of electric devices, sulfide solid electrolytes with high ionic conductivity and high air-stability must be developed. Li3PS4 electrolytes have been used in all-solid-state batteries because of their relatively high ionic conductivity (4 × 10 −4 S cm−1 at 25 °C) and higher air-stability than those of other Li2S–P2S5 type solid electrolytes. Herein, the Li4SnS4–Li3PS4 system was investigated to (1) increase the ionic conductivity of Li3PS4 using excess Li carriers and (2) improve the air-stability of Li3PS4 by introducing air-stable Sn–S bonds. The structure, ionic conductivity, and air-stability of xLi4SnS4·(1−x)Li3PS4 were systematically investigated; the results showed that adding small amounts of Li4SnS4 to Li3PS4 glass and glass-ceramic enhanced their ionic conductivity and air-stability without degrading their electrochemical stability. In particular, the 0.3Li4SnS4·0.7Li3PS4 glass-ceramic showed an ionic conductivity of 8.1 × 10 −4 S cm−1 at 25 °C and generated only a small amount of H2S gas (3 ppm [0.3 cm3 g−1]) when it was dissolved in water. Hence, xLi4SnS4·(1−x)Li3PS4 solid electrolytes can be used as alternatives to the conventional Li3PS4 electrolyte because of their various advantages and a simple preparation method that involves adding only SnS2 to conventional starting materials.

Silicon and carbon containing non-oxide ceramics, such as SiC, SiCN, SiBCN, derived from polymeric precursors show outstanding resistance towards creep and oxidation at high temperatures and harsh atmospheric conditions. These polymer derived ceramics are potential materials for application as protective coatings on carbon and SiC based composites. In the current investigation, a commercially available polyvinylsilazane polymer was doped with molecular source of Ti, crosslinked and pyrolyzed in nitrogen atmosphere, and the evolution of phase and nanostructure was studied. The pyrolyzed SiTiCNO ceramic hybrids appeared predominantly amorphous up to 1000 °C. Exceptionally homogeneous distribution of anatase TiO2 nanocrystals in the size range of 2–12.5 nm was observed throughout the SiCN matrix on high temperature annealing. Such SiCN–TiO2 nanocomposites exhibit enhanced oxidation resistance till 1400 °C. The paper demonstrates easy fabrication of the ceramic nanocomposite, which promise application in high temperature barrier coatings and structural components due to its excellent crystallization and oxidation resistance.

Temperature sensing from the photoluminescence of MgAl2O4:Cr3+ ceramic powder is systematically investigated. Material was prepared by self-propagating high temperature synthesis method. In this host, Cr3+ experiences the strong crystal field, so the overlapping emissions from 2E and 4T2 energy levels are observed. Emission and excitation spectra were recorded from 300 K to 540 K. The broad photoluminescence attributed to 4T2→4A2 emission gains in intensity with increase in temperature on account of 2E→4A2 emission intensity until 460 K when both emissions start quenching. The emissions were separated by deconvolution at each temperature and used for the luminescence intensity ratio temperature readout method. The obtained relative sensitivity exhibited high values in the physiological range, from 3.5 %K−1 at 300 K to 2.9 %K−1 at 330 K, above 2 %K−1 below 400 K and above 1 %K−1 between 400 K and 540 K.

In this paper, we present an efficient and effective method to predict the pressure dependence and temperature dependence of second-order elastic constants (SOECs) by introducing third-order elastic constants (TOECs) in the monocarbide ultrahigh temperature ceramics. The method is validated by comparing with experiments and previous calculations in four TMCs (TM = Nb, Ti, V, Zr). Using this method, we investigate the derivatives of SOECs against pressure and temperature as well as the anisotropic properties of polycrystalline modulus. In addition, we fit the SOECs with pressure and temperature under the framework of CALPHAD for practice usage.

Although TiO2 is a wide band gap semiconductor, it demonstrates photodegradation activity under visible light irradiation after dye sensitization. Compared with esterification between the surface hydroxyl group of TiO2 and the carboxylic group of dyes, electrostatic interaction between TiO2 and dye shows better photosensitized performance. In this work, Bi/Al co-doping anatase titania (Ti1-xBi2x/3Al2x/3O2 (0 ≤ x ≤ 0.3)) is designed to enhance the electrostatic interaction. The effect of Al ions is to enhance the solubility of Bi3+ into titania nanocrystals. A new band gap is generated after high concentration of Bi element doping, which not only promotes the absorption of visible light, but also improves the utilization of photogenerated carriers. Based on the results of transmission electron microscopy, light absorption, photodegradation activity and density functional theory calculations, it is found that bismuth dopant is the electron capture site. It first accumulates electrons through photocatalytic degradation reaction to enhance electrostatic adsorption between the catalyst and the positively charged dye molecules, and finally realizes high-efficiency photosensitization degradation of Rhodamine B. In addition, the sensitized titania has excellent photodegradation recyclability.

The Ab initio molecular dynamics (AIMD) simulation was adopted to elucidate the alumina vacuum carbothermal reduction and nitridation (VCRN) reaction mechanism, and an experimental method was adopted to verify the AIMD results. According to the results, the VCRN reaction occurs only when N2 is adsorbed on both the C and Al atoms. C plays two important roles during the reaction of alumina VCRN: one is to act as a charge exchange carrier for N and Al atoms to catalyze N2 molecule decomposition, and the other is to react with O atoms and reduce Al2O3.

Designing and developing composites with excellent mechanical, friction, and durability properties at low cost has long been highly desirable for the applications of friction materials. Herein, we employed a cost-effective method to obtain bio-based silica (RHC-SiO2) from gasified rice husk carbon (RHC). Subsequently, inspired by the characteristics of RHC-SiO2 and its hardening process, we report a simple and efficient so-called “hybrid pressing and sintering molding” method for manufacturing copper-based friction materials (CFMs). The CFM-R4 (CFM with 4% RHC-SiO2) possesses a unique combination of high hardness (55.50 H V), low density (0.62 g/cm3), low wear rate (0.081%), suitable friction coefficient (0.26), and good durability. Based on the cost-effective method, the increased and decreased stages of RHC-SiO2 yield were determined mainly by reaction rate and compatibility, respectively. Compared with CFM-0 (CFM without SiO2), the CFM with RHC-SiO2 possesses better mechanical and friction properties. In view of high-performance and eco-friendly, such CFM with RHC-SiO2 would hold a promising application in friction fields such as transmission, differential, and synchronizer.

Diamond wire saw cutting technology has been widely used in the slicing of sapphire crystal. The ultra-high hardness of sapphire makes the sawing characteristics of diamond saw wire constantly change. At present, there is a lack of in-depth understanding about the influence of sawing characteristics on the quality of sapphire as-sawn wafer, which leads to the unreasonable matching between the process parameters and the sawing characteristics of the saw wire, and reduces the as-sawn wafer quality and the saw wire life. In this paper, the slicing sapphire crystal experiment was carried out with constant process parameters and the variation of saw wire bow angle, nominal diameter and saw kerf loss, surface morphology and surface roughness of the as-sawn wafer during the whole life cycle of the saw wire from initial cutting to breakage was studied. The evolution mechanism of wear and sawing characteristics in the whole life cycle of saw wire was explored, and a reasonable processing scheme which can match the sawing characteristics was put forward. The research results show that in the whole life cycle of the saw wire, the abrasives emerge from the plating layer in turn, then the cutting edge are blunted, and finally the abrasives are greatly flattened and a small amount of falling off. Saw wire has experienced initial wear, stable wear and sever wear, and the proportion of three stages in the whole life cycle is about 0.3: 0.6: 0.1. Compared with the initial stage of wear and the late stage of rapid wear, the saw wire has higher sawing characteristics and better as-sawn wafer quality in the middle stable wear period. The sawing characteristics of new saw wire is relatively weak at the beginning of cutting, so the feed speed of workpiece should be increased gradually from low to high; When most of the abrasives finish sharpening edge, a relatively stable and high feed speed can be adopted; When the abrasives are obviously flattened or fall off, the feed speed should be decreased to accommodate the significantly reduced. cutting performance of diamond saw wire.

The temperature dependences of the cubic lattice parameters and the molar heat capacities of Ln2О3‧2HfO2 (Ln = Dy, Ho, Er, Tm, Yb, Lu) solid solutions of the defective fluorite structure were determined in the temperature range 300–1300 K. The coefficients of thermal expansion and Cp(T) equations are estimated.

The scaffold of bone repair needs a variety of material combinations to meet its intended performance; a typical single material such as zirconia has excellent mechanical properties, while hydroxyapatite and calcium silicate are bioactive materials with different degradation rates. In this paper, porous zirconia scaffolds were fabricated using 3D printing technology. The surface of the scaffold was coated by dipping with different contents of calcium silicate and hydroxyapatite to improve the biological activity and mechanical properties. Mechanical tests show that the coating material can effectively fill the pores of the porous scaffold, increasing its compressive strength by an average of 55%. The simulated body fluid (SBF) test showed that the higher calcium silicate in the coating increased the degradation rate. Cell experiments showed that the coated scaffolds exhibited good cytocompatibility and were beneficial to the proliferation and differentiation of cells. In conclusion, coated scaffolds have potential applications in the field of bone repair.

In this paper, an agglomerated composite powder of titanium diboride-nickel (TiB2-Ni) was milled and spray-dried. The effects of the sintering method, sintering temperature, holding time, and La2O3-doped on the morphology, phase content and properties of the powder were investigated. The results showed that the microwave-sintered La2O3-doped powder had the best properties when sintered at 1273 K for 15 min. La doping reduced the oxygen content, inhibited the formation of the brittle Ni3B phase, and improved the mechanical properties of the powder. The powder may be a suitable raw material for thermally-sprayed TiB2-Ni coatings.

The proficient realization of Na-ion batteries (NIBs) having exceptional electrochemical behavior is considered to bridge the hurdles triggered by inadequate resources and costly manufacturing of Li-ion batteries. Herein, we report a facile synthesis of Ni0.06Co2.94O4/CNTs hybrid using the solvothermal route and Ni0.06Co2.94O4 using the hydrothermal approach. The formation of a nest-like conductive framework of Ni0.06Co2.94O4/CNT composites, aligning favorably to form an assembly of a layered structure, supports an efficient Na-ion insertion/extraction process. A high initial charge capacity of 621 and 582 mAh g-1 is delivered by Ni0.06Co2.94O4/CNTs and Ni0.06Co2.94O4 electrodes, respectively which retained up to 328 and 239 mAh g-1 after 100 cycles. The electrodes also delivered excellent rate performance with 119 and 93 mAh g-1 at 5.0C and retained 77 and 64% of initial capacity, respectively when recovered from 0.05C. Additionally, Ni0.06Co2.94O4/CNTs exhibited low impedance over a wide range of frequencies resulting in more Na ions storage and a faster Na insertion/extraction process. The exceptional performance shown by the hybrid electrode is due to the synergistic influence flanked by binary metal oxides and CNTs. Hence, the hybrid of Ni-doped metal oxide and carbonaceous species emerge as an excellent choice for use as an electrode for electrochemical energy storage devices.

The influences of cobalt oxide (CoO) additions on the structure, optical transitions, ligand field parameters and stability of lithium phosphate glasses have been investigated. A series of glass systems (LiPhCo-glasses) was successfully prepared through the melt quenching approach. The amorphous nature was confirmed from X-ray diffraction measurements. The density and molar volume followed the typical opposite behavior, where the latter showed a decreasing behavior with CoO additions. Furthermore, it was found that the LiPhCo-glasses gradually changed their color from colorless (Co-free sample) into bluish glasses with CoO additions, thereby evidencing the presence of Co2+ ions. This is consistent with the absorption band identified in the optical absorption spectra at ~562–572 nm, which is related to 4A2(4F) →4T1(4P) electronic transitions of Co2+ (3d7 electronic configuration) in tetrahedral symmetry. Additional absorption band is detected at ~1412–1448 nm, which is correlated to 4A2(4F) →4T1(4F) transitions of Co2+ ions in tetrahedral symmetry. These two absorption bands were employed to study the ligand field splitting ( 10 D q t )and Racah parameter (B), which sheds the light into the bonding character between Co ions and its ligands. The analysis showed that 10 D q t (B) is increased (reduced) indicating more covalency and less stability within the glass matrix with Co additions.

Three series of divalent ions (Co2+/Ni2+/Cu2+) substituted into lithium-manganese ferrites were synthesized using a typical ceramic technique. Two different methods were used to investigate their elastic properties. Infrared (IR) spectroscopy showed two essential bands referring to the tetrahedral ‘υA’ and the octahedral ‘υB’ sites. The force constant, elastic wave velocity and elastic moduli of all specimens have been calculated from the results of IR spectroscopy. Using the ultrasonic pulse transmission (UPT) technique, the longitudinal and shear wave velocities were measured. Using these values; bulk modulus (B), rigidity modulus (G), Young's modulus (E), and Poisson ratio (σ) were determined. In comparison, the elastic moduli resulting from IR spectroscopy results were larger than those obtained from UPT measurements. Because the present ferrite systems are porous, the elastic moduli of the compositions from UPT have been adjusted to zero porosity by two models. The values of the adjusted elastic moduli have been shown to have the same trend as those of the uncorrected elastic moduli. Elastic parameters have generally improved dramatically for Li–Mn–Co ferrite and Li–Mn–Ni ferrite compared to Li–Mn–Cu ferrite. Higher elastic moduli values have been obtained in Li–Mn–Co spinel ferrites, suggesting that such materials are ideal for use in core shapes. Two methods were used to evaluate the Debye temperature of all compositions.

This work presents SrO-BaO-Nb2O5-B2O3-P2O5-K2O-TiO2 glass-ceramics prepared by controlled crystallization method. The uniformly dense microstructure with fine grains can be achieved by introducing TiO2. The structural changes were confirmed by the results of SEM and TEM. The 0.5 mol% TiO2 added glass heated at 750 °C for 2 h demonstrates excellent comprehensive properties of er= 110, BDS = 1408 kV/cm, high energy storage efficiency (η) of 92% and energy storage density of 9.65 J/cm3. The as-prepared glass-ceramic exhibits ultrahigh power density (86.21 MW/cm3), actual discharge energy density (1.00 J/cm3) and excellent temperature stability. These findings qualify this environment-friendly glass-ceramics as one potential candidate for energy storage applications, especially in high power and pulsed power system field.

Metal oxide as a thermoelectric material has shown great attention in recent years due to its outstanding thermal and chemical stability, good oxidation resistance, low cost, etc. This article reports the successful synthesis of tungsten oxide (WO3) nanoparticles and tungsten oxide-reduced graphene oxide (WO3-rGO) nanocomposites and studies of their thermoelectric properties. The structural characteristics of the WO3 nanoparticles and WO3-rGO nanocomposites were examined using XRD and Raman techniques. At 313 K, WO3-rGO nanocomposites exhibit an ~ 8.8 times enhancement in the thermoelectric material figure of merit (zT). These excellent performances are further supported by up to ~ 13.7 times enhanced electrical conductivity and a ~ 56% reduction in thermal conductivity compared to WO3 nanoparticles. It has been concluded that reduce graphene oxide helps in forming a conducting pathway in the WO3-rGO nanocomposites, allowing the easy passage of charge carriers in the matrix.

CO2 methanation is a significant route to decrease carbon emission as well as realize carbon neutrality and has gained considerable concerns from experts in the environment and energy field currently. Herein, highly dispersed ruthenium nanoparticles entrapped in TiO2 nanotubes, labeled as Ru-in/TNT, were constructed and adopted for photo-thermal driven CO2 methanation. The Ru nanoparticles confined in the nanotube exhibited an enhanced CO2 methanation activity, especially under light irradiation. Multiple characterization techniques (XRD, XPS, UV–vis DRS, HRTEM, Raman, etc.) were conducted to reveal the effect of confinement synergy on photo-thermal catalytic performance. A boosted photo-generated electron-hole separation efficiency is achieved as a result of the confinement effect, yielding more hot electrons to accelerate methanation activity. This photo-assisted confinement synergy can be expected for constructing an efficient photo-thermal catalytic system.

Strong absorption, thin thickness, low density and broad band are ideal characteristics of electromagnetic wave absorption (EWA) materials. In this work, ultralight porous carbon hollow nanoboxes (PCHN), which have low density and high specific surface area, are successfully prepared by the vapor deposition and etching process. Excellent EWA performances are achieved in the filler with only 3 wt%. A minimum reflection loss (RLmin)value of −30.46 dB (2.2 mm) along with an efficient absorption bandwidth (EAB) (RL ≤ −10 dB) of 5.44 GHz is achieved. And the EAB (RL ≤ −20 dB, corresponding to 99% absorption) can be tuned in the frequency band of 4.88–17.04 GHz via adjusting the thickness from 6.0 to 1.9 mm. The excellent EWA performance is attributed to conduction loss, interfacial polarization, and good impedance matching. Moreover, the adjacent carbon micro-sheets can provide multiple positions for EW reflection, which prolongs the propagation paths of EW and is conducive to the consumption of EW energy. The light weight, broad band and superior RLmin value make the as-prepared PCHN promising candidates for practical EWA applications.