Control and removal of volatile organic compounds (VOCs) have always been critical issues in the environmental field. Catalytic oxidation has emerged as one of the most promising technologies for VOCs removal due to its low operational temperature, high efficiency, and non-toxic by-products. Perovskite oxides (ABO₃) are recognized as efficient and stable catalysts for the catalytic oxidation of VOCs. To enhance the catalytic efficiency of perovskite-based catalysts, it is necessary to systematically analyze and optimize the design of perovskite oxides to meet the specific requirements for the removal of different VOCs. This paper comprehensively reviews recent advances in the catalytic oxidation of VOCs using perovskite oxides. Firstly, various design strategies for perovskite oxides in the catalytic oxidation of VOCs, including morphology control, A-site and B-site substitution, defect engineering, and supported perovskite catalysts, are introduced, giving a close link between the catalytic performance of perovskite oxides and their material composition, morphology, surface properties (oxygen species, defects), and intrinsic properties (oxygen vacancy concentration, lattice structure). The reaction mechanisms and degradation pathways involved in the catalytic oxidation of VOCs are analyzed, and the prospects and challenges in the rational design of perovskite oxide catalysts and the exploration of reaction mechanisms are outlined.

Volatile organic compounds (VOCs) pose significant risks to environmental quality and human health. To enhance adsorption performance of adsorbents for VOCs, further improvement of the unsaturated metal centers becomes a key factor based on the principle that metal ions can be replaced in metal organic frameworks (MOFs). Here, a one-step solvothermal synthesis system was utilized to dope abundant, cost-effective, and environment friendly Al³⁺ ions into MIL-101(Cr) for preparing Al-MIL-101(Cr). Morphologies and structures of MIL-101(Cr) and Al-MIL-101(Cr) samples, alongside the static adsorption performance for toluene, n-hexane, oil and p-xylene, were analyzed. Static adsorption capacities of toluene, n-hexane, oil, and p-xylene of MIL-101(Cr) were 0.676, 0.621, 0.451 and 0.812 g·g^-1, respectively. When Al³⁺ doping amount reached 0.75 mmol, Al-0.75-MIL-101(Cr) displayed maximum VOCs adsorption capacities (0.911 g·g^-1 for toluene, 0.755 g·g^-1 for n-hexane, 0.713 g·g^-1 for oil, and 0.875 g·g^-1 for p-xylene). The dynamic toluene adsorption behavior was assessed through single-component breakthrough curves. Both dynamic and static adsorption results demonstrate that Al-MIL-101(Cr) possesses excellent VOCs removal capabilities, which are attributed to the extensive specific surface area and augmented unsaturated metal sites.

Nano-calcium phosphate (nCaP) has potential applications in nanomedicine fields such as drug delivery, bioimaging, antibacterial treatment, and bone formation promotion. However, its distribution and metabolic patterns within the body are not yet fully understood and require further in-depth research. This study employs a rare earth europium ion fluorescence labeling method and uses tumor-bearing mice as a model to investigate the distribution and metabolism of two sizes of nCaP (nanodots NDs: (2.53±0.63) nm; nanoparticles NPs: (107.76±25.37) nm×(17.66±1.63) nm) in the liver, spleen, lung, kidney, and tumor tissue. The results showed that after tail vein injection of 200 μL with a mass concentration of 1.5 mg/mL nCaP into tumor-bearing nude rats for 4 h, CaP NPs were primarily distributed in the liver and spleen, accounting for 65.70% and 29.32%, respectively, with 3.83% in the lung, while only 0.84% and 0.32% in the kidney and tumor. This suggests that larger CaP NPs are more easily captured by phagocytes within the reticuloendothelial system (RES). In contrast, compared to CaP NPs, accumulation of CaP NDs in the liver, spleen, and lung decreased significantly by 89.40%, 87.00%, and 88.89%, respectively, while their accumulation in the kidney and tumor increased by 3.67 and 3.06 times. This indicates that smaller particle size facilitates CaP NDs in glomerular filtration for urinary excretion and enhances their tumor-targeting capability. The clearance rates (CLz) of CaP NDs in the liver, spleen, and lung were 6.60, 4.14, and 2.40 times higher than that of CaP NPs, respectively, and 42.29% in the kidney. This indicates that reduced size of CaP NDs facilitates rapid metabolism by phagocytes in the liver, spleen, and lung but also results in reabsorption in the renal tubules. In tumor, the CLz of CaP NDs decreased by 91.9%, much smaller than that of CaP NPs, suggesting that the smaller CaP NDs exhibit significantly enhanced tumor targeting and retention capability. In the meantime, a physiologically based pharmacokinetic (PBPK) model incorporating particle size factors was preliminarily established for tumor-bearing mice to simulate the distribution of nano-calcium phosphate. The model's predictive fit (R²) for CaP NDs and CaP NPs in tumor sites reached 0.925 and 0.827, respectively. This study provides promising support for understanding in vivo distribution and metabolic patterns of nCaP and applying potential in medicine.

Traditional metal-supported solid oxide fuel cells (MS-SOFCs) typically utilize yttria stabilized zirconia (YSZ) as the electrolyte with operating temperature of about 800 ℃. In order to enable MS-SOFC to serve at low temperature, this study used gadolinium doped ceria (GDC), which exhibits higher conductivity at lower temperature, as the electrolyte to facilitate the practical application of MS-SOFC. Tape casting was employed to fabricate thin-film anodes (NiO-GDC) and electrolytes (GDC), while ultrasonic spraying was used to prepare the cathode material La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)-GDC. The resulting components were assembled onto a metal support to construct an MS-SOFC with a thin-film GDC electrolyte, and its electrochemical performance was evaluated. At 650 ℃, the total impedance of the cell was 0.50 Ω·cm², with Ohmic impedance of 0.23 Ω·cm² and polarization impedance of 0.27 Ω·cm², and the maximum power density was 336 mW/cm². The cell was operated at 550 ℃ under a constant voltage of 0.5 V for 100 h without significant degradation. Its electrolyte and anode, which were prepared by warm isostatic pressing and co-sintering, were tightly bonded. After long-term operation, no delamination between layers of the cell was observed, indicating that structural stability ensured the long-term stability of the MS-SOFC. MS-SOFCs in this study prepared via a process route combining tape casting, warm isostatic pressing, and direct assembly, displayed excellent electrochemical performance and long-term stability, providing a new approach for industrial production of low-temperature SOFCs.

As an anode for lithium-ion batteries, silicon material has the advantage of high energy density. However, the volume effect during charge-discharge cycles causes instability in the active coating's surfaces and diffusion stress induced by internal polarization, leading to inevitable structural degradation and capacity fading. Inspired by functionally gradient materials, this study proposed a five-layer composite gradient silicon electrode. Experiments and multi-scale electro-chemo-mechanical coupled model demonstrate that the designed symmetric and linear gradient silicon electrodes effectively mitigate mechanochemical coupled degradation, showing superior cycling and rate performance compared to traditional uniform electrode. Specifically, the symmetric gradient electrode retains a specific capacity of 2065 mAh·g^-1 after 100 cycles at 0.2C (1C=2.65 mA·cm^-2) rate, with a capacity retention rate of 81%, while that of uniform electrode is 51%. The linear gradient electrode exhibits an average discharge capacity 1.5 times that of the uniform electrode at 1C rate. Moreover, both types of gradient electrodes demonstrate smaller impedance variations before and after cycling compared to the uniform electrode. These composite gradient electrodes are implemented through an innovative multi-layer coating process, and improved structural stability and electrochemical performance without material modifications, providing a reference for designing and fabricating high-performance silicon electrodes.

Electrochromic smart windows can regulate indoor light through modulating optical transmittance of electrochromic materials to realize energy-saving buildings. Amorphous tungsten oxide (WO₃) film fabricated by magnetron sputtering technology is the most likely to be industrialized due to its advantages of large-area and uniform deposition. However, electrochromic characteristics of the sputtered WO₃ film lag behind those of the solution-process approach due to inefficient ion transport arising from its intrinsically dense atomic structure. In this work, a strategy to develop microstructured magnetron-sputtered WO₃ films by introducing the buried porous electrodes to improve the optical modulation and response time was proposed. The results demonstrate that the porous sputtered WO₃ films prepared by this method exhibit significantly enhanced electrochromic characteristics compared with the dense WO₃ films. When thickness of the porous WO₃ increased to 300 nm, the optimized electrochromic characteristics were achieved, with a remarkable optical modulation of up to 79.08%, coloring and bleaching times of only 2.6 and 2.0 s, and a high coloring efficiency of 52.5 cm²/C. The improved performance is mainly attributed to synergistic effect of the porous indium tin oxide (ITO) electrode and the porous WO₃ film. The porous ITO electrode can increase the surface area with the increased WO₃ component and then increase electronic charges, facilitating the redox reaction process. Moreover, the porous WO₃ film offers a larger surface area for the electrolyte, increases reactive active sites and shortens ion diffusion pathway, which accelerates the ion diffusion and migration process, realizing efficient redox reactions and fast ion transport. This work provides an effective method for preparing high-performance micro- and nano-structured sputtered electrochromic films.

Laminated Ta/Ta_0.5Hf_0.5C cermets, characterized by high strength, high toughness, and high-temperature resistance, are excellent candidate materials for structural applications in aerospace field. To further investigate ablation performance of Ta/Ta_0.5Hf_0.5C cermets under high-temperature environment, a high-frequency plasma wind tunnel was utilized to evaluate their ablation resistance at nearly 3000 ℃. Their phase composition and microstructure before and after ablation were characterized and analyzed. Results revealed that the laminated Ta/Ta_0.5Hf_0.5C cermets demonstrated remarkable ablation resistance, with a mass ablation rate of 0.061 g/s and a linear ablation rate of 0.019 mm/s. During the ablation process, distinctive ridge-groove surface morphologies and internal cracks were produced along the layered structure direction. These features were attributed to inconsistent ablation rates and thermal expansion coefficients of Ta metal layer and Ta_0.5Hf_0.5C ceramic layer. Specifically, the ridge region primarily consisted of Hf₆Ta₂O₁₇ formed by oxidation of Ta_0.5Hf_0.5C ceramic layer. This compound could stably exist at high temperatures to protect the interior of ceramic layer from further oxidation. In contrast, the groove region primarily comprised Ta₂O₅, which was formed by oxidation of Ta metal layer. Yet Ta₂O₅ had a tendency to melt and vaporize at elevated temperatures, potentially leading to ejection or loss toward the ablation edge. The cracks formed within the layered structure during cooling process after ablation were mainly generated by thermal stress acting on the Ta_0.5Hf_0.5C ceramic layer due to differences in thermal expansion coefficients between the layers. Additionally, the Ta₂C interfaces between metal and ceramic layers played a crucial role in branching, deflecting, and initiating micro-cracks, which endowed the material with good thermal shock resistance.

Deepwater shaft sealing materials are one of the critical core technologies limiting the advancement of deepwater equipment. Silicon carbide (SiC) ceramics, due to their outstanding high modulus, high thermal conductivity, low density, and excellent corrosion resistance, have become an ideal choice for next-generation deep-sea sealing materials. The immense seawater pressure in deep-sea environments causes significant differences in corrosion and wear processes compared to conventional atmospheric pressure conditions. However, research on the corrosion and wear behavior of SiC ceramics in deep-sea environments remains relatively insufficient. In this study, the static pressure of artificial seawater was adjusted to simulate deep-sea conditions at depths ranging from 0 to 5 km. In-situ characterization of the materials’ performance in deep-sea environments was conducted, and the influence of static pressure on their corrosion and wear properties was explored. The results indicated that SiC ceramics exhibited outstanding corrosion resistance in deep-sea environments at depths between 0 and 5 km. After immersion for 200 h, no significant corrosion, oxidation, or seawater salt-related erosion was observed on the material’s surface, and no mass loss occurred. As seawater depth increased, the chemical reaction between SiC and water gradually weakened, further enhancing the corrosion resistance of SiC ceramics. After seawater corrosion, the mechanical properties of SiC ceramics remained stable. Flexural strength of the material decreased by less than 5% after 200 h-corrosion in a 5 km deep-sea environment, and Vickers hardness or fracture toughness changed little. Under seawater lubrication conditions, SiC ceramics exhibited excellent wear resistance, with a wear rate of 2×10^-8-4×10^-8 mm³/(N·m), much lower than that of the paired silicon nitride (Si₃N₄) ceramic material (4×10^-5-1×10^-4 mm³/(N·m)). Notably, as seawater depth increased, both the material’s resistance to water corrosion and the lubricating load-bearing capacity of seawater were significantly enhanced, leading to a decrease in wear rate with increasing depth. In conclusion, SiC ceramics demonstrate significant potential for application in deep-sea sealing technologies.

Fabrication of feedstock powders is a critical technology that directly influences the microstructure and performance of plasma-sprayed coatings. Conventional boron thermal reduction methods for synthesizing high-entropy boride powders encounter several limitations such as prolonged processing time, impurity contamination, and inability to obtain spray-ready powders. In this work, an inductive plasma spheroidization (IPS) process was employed to fabricate (Zr_1/4Hf_1/4Ta_1/4Ti_1/4)B₂ high-entropy powders for plasma spraying in contrast to the other two traditional powder preparation routes. The morphology, internal structure, particle size distribution, density, and other fundamental properties of powders were systematically characterized. The effects of different powder fabricating processes on the microstructure and fundamental properties of high-entropy boride powders were systematically investigated, thereby validating the broad applicability of this methodology for synthesizing high-entropy boride powders. The results demonstrate that using commercial micron-sized boride powders as precursors, a hybrid process combining mixing, spray drying, sintering with IPS facilitates the fabrication of high-entropy powders with homogeneous elemental distribution. The resulting powders exhibit spherical morphology, smooth surfaces, high internal density, and high apparent/tap density. Further experiments on synthesizing different high-entropy borides with varied compositions confirm the extensive applicability of this method. The formation mechanism of high-entropy solid solutions is elucidated through first-principles calculations combined with the unique characteristics of IPS process. This work proposes a promising method for fabricating high-entropy ceramic powders suitable for plasma-spray coatings.

In recent years, ZrB₂, as a representative material of ultra-high temperature ceramics (UHTCs), has become an important candidate material system for components of new generation aerospace vehicles. However, its practical application is limited by difficulties in material preparation and processing of complex components. This study aims to optimize sintering process of ZrB₂-based UHTCs by introducing HfSi₂ as a sintering aid, specifically addressing the challenge of densification caused by low intrinsic diffusion coefficient of traditional ZrB₂ ceramics. The research focuses on elucidating formation mechanism of core-rim structured borides and their role in enhancing densification of ZrB₂-HfSi₂ ceramics. Dense ZrB₂-HfSi₂ ceramics were successfully fabricated via hot-press sintering at 1600 ℃. The results reveal that softening of HfSi₂ phase during sintering effectively fills interparticle gaps, thereby facilitating low-temperature densification. Furthermore, during the holding stage, interdiffusion of Hf and Zr atoms through a dissolution-reprecipitation mechanism facilitates formation of a core-rim structured ZrB₂/(Zr,Hf)B₂ composite. This core-rim structure consists of ZrB₂ core encased by a (Zr,Hf)B₂ rim, characterized by a fully coherent interface (hexagonal P6/mmm symmetry) with a low lattice mismatch (<5%), ensuring interfacial stability. The ZrB₂-HfSi₂ ceramic exhibits a compressive strength of (1333±83) MPa, a Vickers hardness of (15.86±0.72) GPa, and a fracture toughness of (2.01±0.36) MPa·m^1/2. The ZrB₂-HfSi₂ ceramic demonstrates typical intergranular fracture behavior, with only a limited number of cleavage planes displaying core-rim structural features. These findings provide critical insights into low-temperature sintering of UHTCs and underscore potential of core-rim structures in advancing the preparation of high-performance ceramics.

Aluminum nitride (AlN) ceramics exhibit exceptional thermal and electrical properties, making them highly promising candidates for electronic packaging applications and integrated circuits. Nevertheless, the hydrolysis of AlN powder results in formation of Al(OH)₃, which decomposes into Al₂O₃ during the subsequent sintering process. This reaction increases oxygen content, thereby degrading thermal conductivity of AlN ceramics and further imposing significant limitations on their processing and utilization. Consequently, surface modification of AlN powder is imperative to improve its hydrolysis resistance. In this work, a dual-agent modification strategy utilizing polyethylene glycol (PEG) and lauric acid (LA) was implemented through a straightforward wet ball-milling protocol, successfully forming a chemically bonded encapsulation layer on AlN particles. FT-IR and XPS analyses verified that carboxyl groups (-COOH) of LA engaged in esterification reactions with hydroxyl groups on the oxidized AlN surface, leading to formation of robust ester linkages. TEM images revealed a continuous encapsulation layer with a thickness ranging from 12.2 nm to 16.1 nm. Remarkably, the modified powder maintained a solution pH below 9 after 72 h immersion in water at 40 ℃, with no discernible alterations in phase composition and microscopic morphology. This chemically stable and low-solubility encapsulation layer effectively obstructs water diffusion pathways, thereby suppressing hydrolysis kinetics. Enhanced hydrolysis resistance was positively correlated with LA dosage. This work proposes an innovative encapsulation-based paradigm for developing hydrolysis-resistant AlN powders and advancing high-performance ceramic fabrication.

Adsorption by solid amine adsorbent is a promising technology for decarbonization of flue gas. However, adsorption properties of many solid amine adsorbents need to be enhanced, and it is necessary to further study the CO₂ adsorption mechanism. A novel CO₂ adsorbent with high capacity was obtained by grafting 3-aminopropyltriethoxysilane (APTES) on a micro-mesoporous composite molecular sieve ZSM-5/MCM-48 as the support, and then impregnated with tetraethylenepentamine (TEPA) or polyethyleneimine (PEI). The maximum adsorption capacity of APTES-ZSM-5/MCM-48-TEPA-60 (A-ZM-T60), loaded with 60% (in mass) TEPA, for CO₂ reaches 5.82 mmol·g^-1 at 60 ℃ in 15% (in volume) CO₂. Carbamate, alkyl ammonium carbamate and carbonate are generated during the chemical adsorption, which is dominant for CO₂ adsorption because of the reaction between CO₂ and amino groups on the adsorbent, simultaneously accompanied by weak physical adsorption. All above data confirm that these composites display an outstanding adsorption performance with a bright future for CO₂ capture from flue gas after desulfurization.

Lead magnesium niobate-lead titanate (PMN-PT) piezoelectric single crystals are widely utilized due to their outstanding performance, with varying compositions significantly impacting their properties. While application of PMN-PT in high-power settings is rapidly evolving, material parameters are typically tested under low signal conditions (1 V), and effects of different PT (PbTiO₃) contents on the performance of PMN-PT single crystals under high-power conditions remain unclear. This study developed a comprehensive high-power testing platform using the constant voltage method to evaluate performance of PMN-PT single crystals with different PT contents under high-power voltage stimulation. Using crystals sized at 10 mm×3 mm×0.5 mm as an example, this research explored changes in material parameters. The results exhibit that while trend of the parameter changes under high-power excitation was consistent across different PT contents, degree of the change varied significantly. For instance, a PMN-PT single crystal with 26% (in mol) PT content exhibited a 25% increase in the piezoelectric coefficient $d_{31}$, a 13% increase in the elastic compliance coefficient $s_{11}^{E}$, a 17% increase in the electromechanical coupling coefficient $k_{31}$, and a 73% decrease in the mechanical quality factor $Q_{\mathrm{m}}$ when the power reached 7.90 W. As the PT content increased, the PMN-PT materials became more susceptible to temperature influences, significantly reducing the power tolerance and more readily reaching the depolarization temperatures. This led to loss of piezoelectric performance. Based on these findings, a clearer understanding of impact of PT content on performance of PMN-PT single crystals under high-power applications has been established, providing reliable data to support design of sensors or transducers using PMN-PT as the sensitive element.