Nanoscale
·
2025
·
IF 5.1
Shaoyan Zhang,Bing Xie,Jinxia Cai,Shixian Wu,Haishan Xu,Kun Guo,Pu Mao,Haibo Zhang
Polymer dielectrics with superior high-temperature capacitive energy storage capabilities have become increasingly crucial for modern power systems and high-voltage electrical devices. Current polymer dielectrics, however, suffer from high conduction losses when exposed to high temperatures and electric fields, which significantly impede their ability to achieve high discharge energy density (Ue) and efficiency (η). Herein, fluorene polyester (FPE) nanocomposites incorporating ultra-low content Al2O3 nanoplates (NPLs) are presented. At 150 °C, the FPE-based nanocomposites with 1 wt% Al2O3 NPLs exhibit a remarkable Ue of 4.96 J cm−3 and an η of 81% at 520 MV m−1, outperforming most polymer dielectrics. The improvement in Ue is attributed to three key factors: (I) the introduction of a wide bandgap of Al2O3 NPLs enables them to bear high local electric fields and delay the formation of breakdown pathways, leading to an enhanced breakdown strength (Eb) of 520 MV m−1; (II) a minimal loading of Al2O3 NPLs as a deep trap can effectively capture free charges and inhibit the migration of charge carriers in the polymers, thus reducing conductive losses and remnant polarization (Pr); and (III) the small-size and ultra-low content of Al2O3 NPLs can create a high specific surface area that facilitates high Maxwell–Wagner–Sillars interfacial polarization, leading to increased maximum polarization (Pmax). The enhanced Eb and the increased polarization difference (ΔP = Pmax − Pr) together contribute to the substantial improvements in both Ue and η.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Kai Li,Ming Qiang,Jia Tong,Kaichen Qian,Yanna Tian,Bingheng Sun,Long Zhang,Wei Wu,Jintai Fan,Xiaomeng Yin
In this study, Al 2 O 3 -doped Y 2 O 3 -MgO nanocomposite ceramics were synthesized to inhibit abnormal grain growth. Y 2 O 3 -MgO nanopowders were synthesized using a sol-gel combustion approach. Two distinct Al 2 O 3 doping methods were employed: aluminum nitrate doping during the solution preparation stage and aluminum isopropoxide doping during the ball-milling stage of powder preparation processing. This study presents a comparative analysis of the effect of two doping methods on the performance and microstructure of ceramics. Doping during the solution preparation process can provide a more homogeneous distribution of Al 2 O 3 , which facilitated the formation of a minor Y 4 Al 2 O 9 phase. This tertiary phase effectively inhibited abnormal grain growth and improved mid-infrared transmittance. However, Al-O bonds cause a blue shift of transmission cut-off edge and an increase of emissivity, though the practical consequences for device performance require further investigation.
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Jilei Lin,Meiqing Shen,Sifeng Bi,Gurong Shen,Feng Gao,Wei Li
Propylene production via propane dehydrogenation (PDH) over supported platinum (Pt) catalysts is a vital industrial process. However, rapid catalyst deactivation due to coking necessitates periodic regeneration under harsh oxidative conditions. While alloying Pt with transition metals significantly reduces coking, these alloy catalysts often exhibit poor regeneration stability. In this study, we demonstrate that supporting PtIn nanoparticles on Y2O3-modified δ-Al2O3 yields a PDH catalyst with significantly improved activity and stability. This catalyst achieves propane conversion rates close to the thermodynamic equilibrium at an ultralow Pt loading of 0.1 wt %, along with high propylene selectivity. Notably, this catalyst also exhibits remarkable regeneration stability. Through reaction-regeneration cycling experiments with various catalyst formulations, we reveal that the alloy effects between Pt and In are primarily responsible for enhanced catalyst stability under steady-state reaction conditions by suppressing coke formation. Meanwhile, the incorporation of Y2O3 as a support component significantly improves stability during regeneration. Density functional theory (DFT) calculations further elucidate the key factors contributing to the enhanced anticoking properties of the catalyst under PDH reaction conditions.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Yuntian Wan,Zhixiang Liu,Jian Ye,Lulu Wang,Yan Yan,Jiangdong Dai,Xue Lin
Accelerating the redox of M n+ /M n+1 (M = metal) and enhancing the electron transfer efficiency is of great challenges in peroxymonosulfate activation . In this study, Al 2 O 3 pellets were used as the support due to their excellent mechanical strength and thermodynamic stability. FeCoS@Al 2 O 3 pellets were firstly prepared via in-situ assembly of ZIF-67 and Al 2 O 3 pellets, followed by hydrothermal treatment and further sulfuration. Oxygen vacancy (O V ) is a kind of anion defect attributed to lattice oxygen detachment under specific conditions. A series of characterizations and experiments confirmed that FeCoS@Al 2 O 3 pellets possessed more abundant vacancies. Especially, the production of sulfur species remarkably strengthened the conversion of Fe 3+ /Co 3+ to Fe 2+ /Co 2+ that achieved 0.1985 min −1 degradation rate towards tetracycline (TC), which was higher than those of other reported catalysts. More significantly, a fluidized-column catalytic unit endowed the continuous zero discharge of TC with a flowing rate of 5 mL/min. Besides, the mechanism study indicated that the degradation pathway followed an order: 1 O 2 > O 2 · - > SO 4 · - > ·OH. This work provided a generally applicable method to design removable and highly efficient heterogeneous catalysts for wastewater treatment .
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2025
·
IF 3.3
Xinwei Geng,Yongfeng Xia,Ming Zhu,Jun Zhao,Dongxu Yao,Yu-Ping Zeng
Ti 4 O 7 is one of the most promising electrically functional materials among the Magnéli phase. To further broaden its applications in areas such as battery electrodes and pollutant treatment, extensive research has been conducted to optimize its mechanical and electrical properties. In this study, Ti 4 O 7 ceramics, as well as Al 2 O 3 and Ta 2 O 5 -doped Ti 4 O 7 ceramics, are fabricated via hot-press sintering using a solid-state method. While the introduction of secondary phases did not result in a significant improvement in the mechanical properties of Ti 4 O 7 ceramics, the effectiveness of Al–Ta co-doping in enhancing electrical conductivity is validated through three commonly used measurement techniques: the Van der Pauw method, the two-probe method, and the four-probe method, yielding conductivity increases of 46.20, 1.98, and 17.98%, respectively. Detailed electrical characterization further elucidated the electrical features of polycrystalline Ti 4 O 7 ceramics and effect of doping. Furthermore, the reaction between Ti 4 O 7 and Ta 2 O 5 , leading to the formation of the ternary oxide TiTaO 4 , is observed.
研究领域:
材料科学
·
陶瓷材料
·
电气工程
·
固态物理
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
China Foundry
·
2025
·
IF 2.3
Zhai Xiao-fei,Chen Jing-yi,Zhang Xue-qin,Qian Yuan-hong,Chen Rong,Zhang Wei,He Ru-jie
The complex ceramic core used for hollow turbine blades requires a high porosity and a high flexural strength. For a better balance between porosity and flexural strength, ceramic materials with porous structures are preferred. In order to achieve the transition from disordered pore formation to ordered pore formation, Al 2 O 3 ceramic cores with triply periodic minimal surface (TPMS) micro lattice structures with different structural configurations (gyroid, diamond, and neovius) and different volume fractions of lattice structures (30, 40, and 50, vol.%) were designed and prepared by vat photopolymerization 3D printing. The effects of structural configuration and volume fraction of the lattice structure on the following structural shrinkage, microstructure, and flexural strength were investigated. The shrinkage relationship of the three lattice configurations is: neovius>diamond>gyroid. Besides, it is found that with an increase in the volume fraction of the 3D printed Al 2 O 3 ceramic micro lattice structures, their flexural strength correspondingly increases ranging from 54.95 MPa to 139.1 MPa. The maximum average flexural strength of the 3D printed Al 2 O 3 ceramic micro lattice structures is obtained when the structural configuration is diamond and with a volume fraction of 50vol.%, which is 139.1 MPa. Even when the volume fraction of the lattice structure is 30vol.%, that is to say the porosity is 70%, the flexural strength is as high as 50–70 MPa, which can still be maintained at a high level. In addition, when the volume fraction of the lattice structure is a certain value, the sample with diamond configuration has a higher strength. The internal pore morphology, pore size, and porosity of the cores are precisely controlled, achieving both a high porosity and a high strength. Therefore, this study maintains high porosity and high strength simultaneously, providing a new lattice structure design idea for 3D printed ceramic cores.
研究领域:
材料科学
·
机械工程
·
陶瓷工艺
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Wenqiang Hu,Wenbin Fu,Samik Jhulki,Liang Chen,Aashray Narla,Zhijian Sun,Fujia Wang,Alexandre Magasinski,Gleb Yushin
Poor heat/flame-resistance of polyolefin (e.g., polyethylene and polypropylene) separators and high flammability of organic electrolytes used in today's lithium-ion batteries (LIBs) may trigger rare yet potentially catastrophic safety issues. Here, we mitigate this challenge by developing a heat-resistant and flame-retardant porous composite membrane composed of polyetherimide (PEI) and Al 2 O 3 nanowires (NWs). The membranes are fabricated based on an industrially scalable non-solvent-induced phase separation process, which results in an intimately interconnected porous network of Al 2 O 3 NWs and PEI . The produced composite membranes exhibit excellent flexibility, thermal stability, and flame-retardancy. Importantly, the composite membranes exhibit minimal thermal shrinkage and superior tensile strength (16 MPa) at temperatures as high as 200 °C, significantly exceeding the performance of conventional polyolefin separators. Compared with commercial separators, their superior wettability and higher ionic conductivity (by up to 2.4 times) when filled with the same electrolyte, larger electrolyte uptake (∼190 wt.%), as well as improved cycle and rate performance demonstrated in LiNiMnCoO 2 (NCM)-based LIBs make them attractive choices for a variety of electrochemical energy storage devices.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Juan Liu,Wen-Ying Li,Jie Feng,Xiang Gao
The hydrodenitrogenation of nitrogen-containing heterocycles over noble metals has fundamental importance for energy and environmental science. To develop more efficient catalyst, mechanistic investigation has been conducted with a method combining in situ Fourier transformation infrared experiments and density functional theory calculations in this work. The in situ experiments indicate flatly adsorbed pyridine molecules convert to pyridinium and α -pyridyl species at higher temperature on metallic Pt of Pt/γ-Al 2 O 3 catalysts. Pyridine hydrogenation distinctly takes place at 150 °C with the appearance of methylene stretching vibrations, and a stepwise mechanism is identified as the temperature further increases. The adsorption, hydrogenation and hydrogenolysis of pyridine on Pt are studied in detail by theoretical calculations. In line with these findings, the geometry optimization confirms pyridine preferentially adsorbs on Pt(111) and Pt(211) both in a parallel configuration. Based on the Langmuir–Hinshelwood mechanism, the results show successive hydrogenation markedly lowers the energy barrier for subsequent hydrogenolysis. The C N bond cleavage occurs via nucleophilic attack of pentahydropyridine, rather than piperidine, which determines the reaction products, including piperidine, n -pentylamine and n -pentane. The comparative study reveals both hydrogenation and hydrogenolysis are kinetically and thermodynamically more competitive on Pt(211) than Pt(111). Especially for hydrogenolysis, the coordinatively unsaturated Pt step atoms play an essential role in C N bond cleavage. Thus, hydrogenolysis is more geometric‒dependent than hydrogenation. This provides instructive information for the design of catalysts with adjustable product selectivity.
研究领域:
催化化学
·
环境科学
·
计算化学
·
能源科学
·
表面化学
✓ 已验证
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2016
·Vol. 47
·期 5
·2830-2836
·
IF 1.474
Long Hongming,Wu Xuejian,Chun Tiejun,Di Zhanxia,Yu Bin
In this study, the assimilation behaviors between calcium ferrite (CF), calcium diferrite (CF 2 ) and sintered Al 2 O 3 , and MgO were explored by an improved sessile drop technique, and the interfacial microstructure was discussed. The results indicated that the apparent contact angles of CF slag on Al 2 O 3 and MgO substrate were 15.7 and 5.5 deg, and the apparent contact angles of CF 2 slag on Al 2 O 3 and MgO substrate were 17.9 and 7.2 deg, respectively. Namely, CF and CF 2 slag were wetting well with Al 2 O 3 and MgO substrate. The dissolution of Al 2 O 3 substrate into the CF and CF 2 slag was found to be the driving force of the wetting process. For the CF-MgO and CF 2 -MgO substrate systems, CaO contrarily distributed with MgO after wetting. For the CF-MgO system, after wetting, the slag was composed of CF and C 2 F, and most of the Fe 2 O 3 permeated into substrate and formed two permeating layers.
研究领域:
材料科学
·
冶金学
·
陶瓷学
·
高温化学
✓ 已验证
DOI
高影响因子
AICHE JOURNAL
·
2017
·Vol. 63
·期 11
·4911-4919
·
IF 2.836
Tengfang Wu,Gang Liu,Liang Zeng,Guodong Sun,Sai Chen,Rentao Mu,Sika Agbotse Gbonfoun,Zhi-Jian Zhao,Jinlong Gong
Supported VO x catalysts are promising nonoxidative propane dehydrogenation (PDH) materials for their commercially attractive activity and propylene selectivity. However, they frequently suffer from rapid deactivation caused by coke deposition. This article describes the promoting role of magnesium on the stability of VO x /Al 2 O 3 catalysts for PDH. A series of VO x /Al 2 O 3 and Mg-modified VO x /Al 2 O 3 catalysts were synthesized by an incipient wetness impregnation method. The catalysts were carefully characterized by Raman spectra, UV-Vis spectra, STEM, TGA and in situ DRIFTS. We showed that the stability of a 12V/Al 2 O 3 catalyst was significantly improved on addition of small amounts of MgO. Experimental evidences indicate that V 2 O 5 nanoparticles emerge in the 12V/Al 2 O 3 samples, and appropriate Mg addition helps dispersing the V 2 O 5 nanoparticles into 2D VO x species thus decreasing coke formation and improving stability in nonoxidative dehydrogenation of propane. © 2017 American Institute of Chemical Engineers AIChE J , 2017
研究领域:
催化化学
·
工业催化
·
材料化学
·
能源化工
·
多相催化
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Li Feng,Zhipeng Hu,Junpeng Cui,Chao Ma,Bo Cheng
Corrosion protection of structural materials in high temperature molten salt environments remains a critical challenge for the development of spent fuel reprocessing technologies. In this study, Al 2 O 3 ceramic coatings were deposited on 316L stainless steel by atmospheric plasma spraying (APS), and vacuum heat treatment (VHT) was applied to tailor the phase composition and microstructural characteristics. The high-temperature corrosion behaviors of the VHT-treated and as-sprayed coatings were systematically investigated in LiCl-KCl molten salt at 600 °C. The results showed that annealing the as-sprayed coating at 1000 °C for 4 h resulted in the near disappearance of metastable γ-Al 2 O 3 diffraction peaks and the formation of a δ-Al 2 O 3 dominated phase composition. Meanwhile, the porosity decreased from 5.33% to 2.86%, and an elemental interdiffusion layer of approximately 21 μm formed across the NiCrAlY bond coat and 316L substrate interface. The adhesion/cohesion strength increased from 15.80 ± 0.17 MPa for the as-sprayed coating to 41.07 ± 0.31 MPa for the VHT-treated specimen. During molten salt exposure, the as-sprayed specimen exhibited pronounced spallation after 80 h, whereas the VHT-treated specimen maintained structural integrity even after 320 h. The improved corrosion durability is mainly attributed to VHT-induced phase stabilization, coating densification, enhanced interfacial continuity, and improved bonding performance, which effectively impede molten salt ingress along defect-assisted pathways and suppress spallation associated with the accumulation of interfacial corrosion products.
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2026
·Vol. 109
·期 8
·e71084
·
IF 4.2
Jiahui Jiang,Jing Li,Yanna Tian,Hui Lin,Yang Tang,Junwei Zhang,Hao Chen,Fan Liu,Ruijin Hong,Zhaoxia Han,Dawei Zhang
Ce:LuAG ceramic phosphors are promising green phosphor conversion materials for high-brightness lighting and display. However, despite its excellent resistance to thermal quenching, Ce:LuAG still suffers from thermal drop of the luminescence under high-power excitation, particularly under ultra-high-brightness laser excitations. This work investigated the effects of excessive Al 2 O 3 addition to the Ce:LuAG ceramic phosphor combined with vacuum brazing on the luminescence thermal stability. Experimental results indicate that 10 wt.% Al 2 O 3 addition improves the Ce:LuAG ceramics microstructure, thermal conductivity, and in result enhances the comprehensive luminescence performance. Cross-sectional BSE and EDS analysis reveals a dense, crack-free brazed interface with Ti enrichment at the ceramic/braze boundary, confirming the formation of a Ti-O reaction layer that enables chemical bonding and efficient heat dissipation. The sample with an additional 10 wt.% Al 2 O 3 brazed at 870°C achieves light conversion efficiency of 253 lm·W −1 at an excitation light power of 2 W, with light conversion efficiency drop of only 10% at a light power of 8 W. (For the samples without additional 10 wt.% Al 2 O 3 , the light conversion efficiency drop exceeds 15.5% at an excitation light power of 8 W.) With light output exhibiting good linear correlation with excitation blue laser power across the 0–30 W range ( R 2 = 0.99784). The illuminance of the ceramic increased linearly within the 10–80 W range, the brazed sample at 870°C reached 2.05 × 10 4 lx under a light excitation power of 90 W, exhibiting better luminescence thermal stability than the Ce:LuAG ceramic phosphors without excessive Al 2 O 3 addition. The combination of excessive Al 2 O 3 addition and vacuum brazing is an effective solution for achieving robust luminescence from Ce:LuAG ceramic phosphors toward high-power laser excitations.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）