Silicon carbide (SiC), as a representative wide bandgap semiconductor material, has increasingly demonstrated its significance in high-power, high-frequency and high-temperature electronic device applications. In recent years, SiC semiconductors have become primary material for power devices in electric drive modules and charging modules of new energy vehicles. Compared to Si-based insulated gate bipolar transistors (IGBTs), a kind of minority carrier device, SiC materials enable high-voltage resistance through majority carrier devices (such as Schottky barrier diodes and metal-oxide-semiconductor field-effect transistors (MOSFETs)) with high-frequency device structures, which conversely allows SiC to simultaneously achieve key characteristics of low on-resistance and high frequency. It is easy to deduce that, SiC will also play an indispensable role in emerging fields such as electric aircrafts, electric vertical take-off and landing (eVTOL) vehicles for low-altitude transportation, augmented reality (AR), photovoltaic inverters, and rail transportation. Among various SiC polytypes, 3C-SiC stands out due to its unique cubic crystal structure, higher thermal conductivity (500 W/(m·K)) and channel mobility (approximately 300 cm²/(V·s)), showcasing significant application potential and research value. This paper provides an overview of the crystal structure, fundamental physical properties, application advantages, and major growth methods of 3C-SiC, including chemical vapor deposition (CVD), continuous-feed physical vapor transport (CF-PVT), sublimation epitaxy (SE), and top-seeded solution growth (TSSG). Research progress and the latest achievements in 3C-SiC crystal growth using above techniques are reviewed, focusing on the thermodynamic characteristics and growth mechanisms of vapor-phase and liquid-phase methods. The microscopic processes of crystal growth are analyzed and summarized, and the future development directions and application prospects for 3C-SiC crystals are discussed.

Pb(II) pollution in water constitutes a serious form of heavy metal pollution that endangers both ecological environment and human health. As an effective sewage treatment technology, adsorption has been considered an economic and common method because of its low cost, environmental friendliness and easy operation. Graphene oxide (GO), an innovative material with superior properties, has garnered extensive research as an ideal adsorbent. Nonetheless, GO still faces many challenges in practical applications due to its limited surface functional groups, suboptimal adsorption selectivity and poor regenerative properties. Current main research focuses on developing various modification strategies to enhance the adsorption performance of GO. In this paper, modification methods of GO and their adsorption mechanisms are reviewed. Firstly, three strategies for improving Pb(II) adsorption properties of GO-based materials are introduced, including N/S functionalization, morphological alteration and magnetization. Their adsorption properties covering adsorption capacity, adsorption selectivity, regeneration, and other performance metrics of GO-based adsorbents are evaluated. Subsequently, the adsorption mechanisms of Pb(II) by GO-based adsorbents such as physical adsorption, electrostatic attraction, ion exchange, and surface complexation are summarized to develop highly efficient GO-modified materials. Finally, the future development of GO-based materials for Pb(II) adsorption is prospected. This review provides novel insights for rational design of emerging GO-based adsorbents and serves as a reference foundation for research and application of GO-modified materials in Pb(II) treatment.

As the operating temperature of aero-engine rises, degradation of thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) on hot-section components affected mainly by infiltration of calcium-magnesium-alumina-silicate (CaO-MgO-AlO_1.5-SiO₂, CMAS) has garnered increasing attention. Rare earth constituents play an essential role in forming corrosion products and subsequent melt penetration when conventional TBCs and EBCs are attacked by CMAS deposits. This study focused on preparation of a series of gadolinium-ytterbium oxides ((Gd_xYb_1-x)₂O₃, x=0, 0.05, 0.10, 0.20, 0.30, 0.50 and 1.00), with particular emphasis on the roles of ytterbium and gadolinium. Their reaction with CMAS deposits was systematically investigated at 1300 ℃ to explore the synergistic mechanism associated with these two rare earth elements. The results indicate that gadolinium cations can efficiently induce the crystallization of products with apatite structure which have a low melt consumption. Conversely, ytterbium cations can induce the formation of products with garnet and silicocarnotite structure which have sluggish kinetics. Furthermore, partitioning of gadolinium and ytterbium ions within corrosion products, along with variation of residual CMAS melt composition, was further analyzed. It is proposed that these two rare earth ions exhibit a synergistic effect within a certain composition range (5%-20% (in mole) of gadolinium content). The optimized ratio of gadolinium and ytterbium within coatings is anticipated to promote apatite crystallization, prevent melt penetration, and modify the sluggish crystallization kinetics of garnet and silicocarnotite, thereby significantly improving the melt consumption. This investigation on synergistic effect of gadolinium and ytterbium cations provides a theoretical support for the anti-CMAS-corrosion composition modification of TBCs/EBCs.

Hexagonal boron nitride (h-BN) ceramics are significant in industrial applications, however, their special layered structure, combined with low strength and hardness, limits their application. In this study, ytterbium aluminum silicate (YbAS) glass and hard SiC particles were simultaneously introduced as reinforcing phases, and a series of h-BN/YbAS/SiC composites were prepared by in-situ reaction hot pressing sintering techniques. With the volume fraction of YbAS glass fixed at 30%, the effect of SiC content on the properties of the composites was studied. The results demonstrate that the synergistic effect of YbAS glass and SiC can effectively enhance the strength and toughness of h-BN-based composites. This composite exhibits optimal mechanical performance when the SiC volume fraction reaches 30%, yielding flexural strength, compressive strength, fracture toughness, Vickers hardness, and elastic modulus values of (462±5) MPa, (1465±58) MPa, (5.5±0.3) MPa·m^1/2, (4.7±0.3) GPa, and 140 GPa, respectively. The strengthening mechanism is identified as when the SiC content reaches a certain proportion, it plays a supporting role, effectively bearing external loads to enhance the composites. Moreover, SiC can effectively suppress the growth of h-BN grains during the sintering process, contributing to fine-grained strengthening. The composites also have good high-temperature mechanical properties and relatively low thermal conductivity, with the thermal expansion coefficient being related to structure of h-BN and transition temperature of YbAS glass. This study provides an effective approach for the strengthening and toughening of h-BN ceramic materials.

Traditional wave-absorbing materials often exhibit performance limitations at high temperatures, which makes it difficult to meet performance demands in extreme high-temperature environments. Fe₂AlB₂ has garnered significant attention in the field of high-temperature wave absorption due to its nano-layered structure and exceptional high-temperature stability. This study synthesized Fe₂AlB₂ powder through a wet ball milling process followed by sintering in an argon atmosphere. Investigation was conducted to elucidate the oxidation mechanisms and to assess the evolution of its wave-absorbing properties at elevated temperatures. Additionally, electromagnetic simulation software was utilized to model the radar cross-section associated with its absorption process under 7 GHz microwave irradiation. The results indicate that the onset oxidation temperature of Fe₂AlB₂ is 671 ℃. As the oxidation temperature increases, a dense Al₂O₃ protective film forms on its surface, significantly enhancing its oxidation resistance. Beyond 1000 ℃, this Al₂O₃ film fractures, leading to transformation of the primary phases into Fe₂O₃, Al₄B₂O₉ and amorphous B₂O₃. Within the oxidation temperature range of 300-800 ℃, the wave absorption performance of the sample progressively improves with increasing oxidation temperature, exhibiting particularly outstanding dielectric loss capabilities around 10 GHz. At an oxidation temperature of 900 ℃, the sample achieves a reflection loss of -42.60 dB at a frequency of 11.28 GHz, with corresponding a thickness of 2.8 mm. The Al₂O₃ film significantly enhances dielectric loss efficiency by inducing interfacial polarization loss at the "oxide film-matrix" interface. This study elucidates that oxidation mechanisms of Fe₂AlB₂ at varying temperatures and examines consequent impacts on wave-absorbing properties, thereby providing a theoretical foundation for its application in high-temperature wave-absorbing environments.

Skutterudite-based CoSb₃ materials have attracted significant attention in thermoelectric applications due to their environmental friendliness, thermal stability and excellent thermoelectric properties. While considerable progress has been made in the development of n-type skutterudite thermoelectric thin films, research on high-performance p-type filled skutterudite flexible thin films remains limited, particularly in the context of flexible device integration. In this work, p-type Ce_0.9Fe₃CoSb₁₂ thin films were deposited on glass substrates via radio frequency magnetron sputtering, and influence of sputtering power (100-120 W) on the film composition, microstructure, and thermoelectric properties was systematically investigated. The results reveal that increasing the sputtering power leads to a gradual decrease in the Ce/Fe atomic ratio and a corresponding increase in the hole concentration, which enhances the electrical conductivity (σ) but reduces the Seebeck coefficient (S). The film deposited at 110 W exhibits the highest thermoelectric performance, achieving a power factor (PF) of 76.7 μW·m^-1∙K^-2 at room temperature and 103.5 μW·m^-1∙K^-2 at 500 K. Building upon these findings, flexible Ce_0.9Fe₃CoSb₁₂ films were further fabricated on polyimide (PI) substrates with substrate heating applied during deposition to improve interfacial adhesion. A flexible thin-film thermoelectric generator was successfully integrated, and its potential application in temperature sensing was evaluated. The device demonstrates excellent mechanical flexibility and reliable thermal sensing performance, highlighting its promise for use in flexible thermoelectric sensor technologies.

Two-dimensional planar metal polyphthalocyanine is considered a kind of promising organic thermoelectric material due to its unique molecular structure and high carrier mobility, but its low carrier concentration and low electrical conductivity impede improvement of thermoelectric performance. In this work, copper polyphthalocyanine/single-walled carbon nanotubes (CuPPc/SWCNTs) composites were prepared by in-situ polymerization and mechanical ball-milling, respectively. As compared with ball-milled sample (BM-CuPPc/SWCNTs), in-situ polymerized sample (IS-CuPPc/SWCNTs) presents strong π-π conjugation between CuPPc and SWCNTs, which can effectively reduce the interfacial resistance between CuPPc and SWCNTs. Therefore, IS-CuPPc/SWCNTs shows higher electrical conductivity than BM-CuPPc/SWCNTs at high SWCNTs concentration. With 80% (in mass) SWCNTs, the electrical conductivity of IS-CuPPc/SWCNTs reaches 1.31×10⁴ S·m^-1, 30% higher than that of BM-CuPPc/SWCNTs, and six orders of magnitude higher than that of pure CuPPc. Meanwhile, the maximum thermoelectric power factor of IS-CuPPc/SWCNTs reaches 18.24 μW·m^-1·K^-2, which is higher than that of BM-CuPPc/SWCNTs and surpasses that of pure CuPPc by six orders of magnitude. This study provides an effective way to enhance the thermoelectric properties of metallic polyphthalocyanine.

Cr poisoning is an important factor restricting the practical application of solid oxide fuel cell (SOFC) cathodes. In particular, the alkaline earth-rich perovskite oxide cathodes are prone to cation segregation and impurity poisoning at high temperatures, which can significantly reduce the cathode performance. To improve the Cr resistance of the cathode, the acid site of SrCo_0.9Ta_0.1O_3-δ (SCT) was regulated by Ag doping, whose conductivity, catalytic activity, surface morphology, and composition were then systematically investigated. The results show that Ag doping enhances the conductivity of the material, and the doped material exhibits higher oxygen surface exchange coefficient, which is conducive to improving its cathodic catalytic activity. At 700 ℃, polarization resistance (R_p) of Sr_0.9Ag_0.1Co_0.9Ta_0.1O_3-δ (SACT10) cathode is 0.0176 Ω·cm², significantly lower than that of SCT cathode (0.0366 Ω·cm²). In addition, due to the Ag doping strategy, the average valence state of Co in SACT10 material increases, which further increases the relative acidity and improves the Cr resistance. After operating in Cr-containing atmosphere for 22 h, R_p of SACT10 cathode is 0.205 Ω·cm², significantly lower than that of SCT cathode (0.964 Ω·cm²), and fewer inert secondary phases are observed on the surface of SACT10 cathode after testing. All above results confirm that Ag doping can effectively increase acid sites, improve activity and enhance Cr resistance. SACT10 obtained in this work is expected to be a promising medium temperature SOFC cathode material.

Synergistic innovation of solar energy collection and storage technology provides an important direction for constructing a new type of self-supply system, in which photo-assisted charging supercapacitor has become a research hotspot due to their unique photo-induced charge storage mechanism and fast charging/discharging characteristics with high power density and fast charging/discharging characteristics, which provides an efficient, environmentally friendly, and sustainable new strategy for energy harvesting and storage in wearable electronic devices and other related products. In this work, ZnFe₂O₄ was synthesized by hydrothermal method and employed as the supercapacitor photoanode, while reduced graphene oxide hydrogel (rGH), prepared using an improved Hummers method followed by hydrothermal treatment, served as the cathode, and Zn(CF₃SO₃)₂ aqueous solution was used as the electrolyte to construct an aqueous photo-assisted charging supercapacitor. The results from the synthesized products, including phase composition, microscopic morphology, chemical structure, light absorption properties, and photoelectrochemical performance of the supercapacitor, show that under the photoelectrical synergistic charging conditions (a current density of 0.2 A·g^-1 and a light intensity of 95 mW·cm^-2), specific capacity of supercapacitor reaches 148 F·g^-1, 17% higher than that under only electric charging conditions. The capacity retention rates of the device are 80% and 90% after 10000 cycles under only electric charging and photoelectric synergistic charging, respectively. Based on all above results, the constructed aqueous photo-assisted charging supercapacitor exhibits high specific capacity and excellent cycling stability, demonstrating promising potential for applications in wearable electronics and related fields.

Nitrogen oxides (NO_x), as main atmospheric pollutants in China, are usually removed through ammonia selective catalytic reduction (NH₃-SCR) technology to achieve ultra-low emissions. Low-temperature NH₃-SCR has gained much attention due to its low energy consumption and cost. However, MnO_x-based catalysts generally suffer from insufficient stability and are susceptible to SO₂ and H₂O poisoning at 120 ℃. To improve the denitrification performance of MnO_x-based catalysts under low temperature and lean flue gas conditions, CeO₂/MnO_x catalysts were prepared by precipitation-calcination decomposition method in this study. Influence of CeO₂ modification on structure, surface properties and low-temperature NH₃-SCR performance of catalyst was systematically studied. Combining first principles calculations, influence of CeO₂ modification on catalytic mechanism for reducing activation energy of the reaction was revealed at microscopic level. The results showed that addition of CeO₂ refined micro particle size of catalyst, reduced proportion of main crystalline phase MnO₂, significantly increased concentration of weak acid sites in the catalyst, augmented proportion of Mn³⁺/Mn and O_α/O, and improved surface acidity and redox performance of the catalyst. The prepared Mn10Ce3 and Mn10Ce5 catalysts achieved a NO conversion rate of over 98%, maintaining stability even at 120 ℃. Addition of CeO₂ dispersed the aggregated MnO_x and reduced concentration of Mn⁴⁺ distribution, which to some extent hindered excessive oxidation of NH₃ and NO by high valence Mn⁴⁺, thereby suppressing N₂O formation and improving N₂ selectivity of the catalyst. First principles calculations further confirmed that CeO₂ modification reduced the activation energy of various intermediate states in reaction pathway, lowering the reaction temperature and improving the low-temperature NH₃-SCR efficiency.

Electrocaloric refrigeration technology has emerged as a research hotspot in solid-state cooling due to its advantages of high energy efficiency, miniaturization potential and environmental friendliness. However, achieving a large adiabatic temperature change (ΔT) and a wide operation temperature (T_span) under low electric fields remains challenging. In this study, a new type of ceramics, (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT, x=0.08, 0.10, 0.12, 0.14) ferroelectric relaxor with different PT contents, was synthesized via a conventional solid-state reaction method. The influence of PT concentration on their electrocaloric performance was investigated. Results indicate that increasing PT content weakens their relaxor characteristics, reduces their dielectric frequency dispersion, and drives their relaxor ferroelectric behavior toward normal ferroelectric. Notably, the 0.88PMN-0.12PT ceramic exhibits outstanding electrocaloric properties under a low electric field of 50 kV/cm, achieving a maximum ΔT of 1.60 K, with ΔT exceeding 0.5 K across a broad temperature range of 30-180 ℃. Piezoresponse force microscopy (PFM) reveals its uniformly distributed long-range ferroelectric domain structure. The electrocaloric effect originates from entropy changes induced by transition of ferroelectric domains from an ordered to a disordered state during electric field unloading. By integrating dielectric, ferroelectric and domain structure analyses, the diffuse phase transition of relaxor ferroelectrics is correlated to their wide-temperature-range electrocaloric performance. This study provides theoretical guidance for designing lead-based electrocaloric materials compatible with low-field driving and wide temperature ranges, which has potential for applications in solid-state refrigeration devices.

CdS quantum dots have a quantum size effect, while photoluminescence wavelength can be regulated by manipulating their sizes, both of which show application potentials in many fields such as fabrication of micro-nano optical devices. With the development of ultrafast laser technology, femtosecond lasers have gradually been delved in the micro-nano manufacturing and optical property regulation of the optoelectronic materials. However, photoluminescence modulation of CdS quantum dots by the femtosecond lasers has never been achieved. This work aims at preparation and photoluminescence modulation of CdS quantum dots based on glass matrix by using femtosecond laser direct writing, and explores their applications in fields such as optical storage and information encryption. In the experiment, five groups of borosilicate glasses with different CdS contents were prepared via a melt quenching method, and the glass samples were finely polished for the subsequent femtosecond laser processing. Due to the local thermal accumulation effect generated by the femtosecond laser, CdS quantum dots can be directly written and precipitate inside the glass. Morphology, microstructure size and dispersion of CdS quantum dots precipitated inside the glass were analyzed by transmission electron microscopy. By changing the laser parameters to regulate size of the precipitated quantum dot spot, continuous regulation of the spot size of laser-induced processing within the range of 5.33-12.28 μm and modulation of the emission wavelength within the range of 540-610 nm were achieved. Finally, it was demonstrated that femtosecond lasers could direct write on the CdS quantum dots in fields such as information encryption and storage.

For high power lasers, the thermal effect imposes a limit on the power density dissipated inside the gain element, while it can be reduced by increasing the size of gain medium, which enhances heat dissipation. However, when aspect ratio of the gain medium increases, spontaneous fluorescence can be drastically amplified. Transverse propagation of spontaneous fluorescence induces amplified spontaneous emission, triggering detrimental parasitic oscillations. A promising solution involves applying cladding layers to the lateral surfaces of gain media to absorb stray radiation. For high repetition rate nanosecond high power solid-state lasers, it is essential to choose gain media with moderate saturation flux. Among these, Nd:LuAG transparent ceramics have shown significant potential due to their outstanding optical, mechanical, and thermodynamic properties. Additionally, Sm:LuAG transparent ceramics, with a high absorption coefficient at 1064 nm, excellent theoretical optical transmittance at 808 nm, and a refractive index similar to that of Nd:LuAG, have emerged as one of the best materials for cladding Nd:LuAG laser ceramics. Here, the 5% Sm:LuAG/1% Nd:LuAG (in atom) cladding laser ceramics (φ56.0 mm×4.8 mm) using commercial Lu₂O₃, α-Al₂O₃, Nd₂O₃ and Sm₂O₃ powders as raw materials were fabricated by vacuum pre-sintering at 1825 ℃ for 20 h and HIP post-treatment at 1750 ℃ for 3 h with TEOS and CaO as sintering additives. The in-line transmittance of the gain area is 81.5% at 1064 nm, while that of the cladding area is 78.6% at 808 nm.

Silicon carbide fibers are considered ideal reinforcing materials for ceramic matrix composites due to their excellent mechanical properties and high-temperature performance. Different types of fibers necessitate individual investigation due to variations in their composition and fabrication processes. This study presents a comprehensive investigation into evolution of the mechanical properties, surface microstructure, and composition of Shicolon-II fibers subjected to argon heat treatment at temperatures ranging from 1300 ℃ to 1700 ℃. The Shicolon-II fibers are composed of small-sized β-SiC grains, SiC_xO_y amorphous phase, and a minor amount of graphite microcrystals. Following treatment in an argon atmosphere at 1300 ℃, the fibers maintain a monofilament tensile strength of 3.620 GPa, corresponding to a retention of 98.32%. This strength diminishes to 2.875 GPa, equating to a retention of 78.08%, after treatment at 1500 ℃. The reduction in mechanical properties of the fibers can be ascribed to the decomposition of the amorphous phase and the growth of β-SiC grains. Furthermore, creep resistance is an essential factor influencing the long-term performance of composite materials. After treatment at temperatures above 1400 ℃, the high-temperature creep resistance of the fibers is significantly enhanced due to growth of β-SiC grains. This study offers valuable theoretical insights into high-temperature applications of second-generation fibers, contributing to an enhanced understanding of their performance under extreme conditions.

Development of high performance, flexible piezoelectric nanogenerators (PENGs) is critical for advancing self-powered sensing and microelectronic applications. In this study, a hydrogen-bond substitute strategy was employed to fabricate a multi-layer PENG based on a cellulose/polyvinylidene fluoride (PVDF) blend film matrix, incorporating multi-phase BCZT (0.1BaZr_0.2Ti_0.8O₃-0.9Ba_0.7Ca_0.3TiO₃) ceramic fillers. Structural characterization via SEM and TEM revealed that an intricate hydrogen-bond network facilitated the uniform dispersion of ceramic fillers within the composite film’s sub-layers. In order to study the effect of filler distribution on piezoelectric performance, the single- and double-layer composite films with varying BCZT configurations were produced and evaluated. The results demonstrated that double-layer PENGs exhibit significantly enhanced electrical output compared to their single-layer counterparts, with the D-L₃H₇ configuration achieving an open circuit voltage (V_OC) of 23.13 V and a short circuit current (I_SC) of 8.32 μA. This enhancement is attributed to increased inter-layer interfaces, which effectively suppressed charge injection and migration, leading to improved charge density. Additionally, the presence of sharp tipped hexagonal tetragonal phase nanoparticles induced an electric field enhancement effect, further optimizing performance.