CERAMICS INTERNATIONAL
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2020
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IF 3.83
Junxiao Tang,Wei Ji,Jingjing Xie,Yunwei Shi,Yuexu Zhu,Qianglong He,Weimin Wang
In this study, B 6.5 C-TiB 2 -SiC-BN composite was fabricated via reactive hot pressing from a powder mixture of TiCN, B, and Si. The reaction process of the powder mixture was investigated by heat treatment at elevated temperatures. The as-reacted powder products possessed a core-shell structure of TiB 2 surrounded by h-BN. During densification, the h-BN in this structure acts as a diffusion channel and lubricant, which promoted the densification process. The extremely small size, fresh surface of in-situ formed phases, and uniform dispersion in synthesized powders also contributed to sintering. The designed reactive hot-pressing sintering effectively resolves the difficulty of obtaining uniformly-dispersed BN. The obtained bulk B 6.5 C-TiB 2 -SiC-BN composite ceramic shows high relative density (98.8%) and good comprehensive mechanical properties including hardness, bending strength , and fracture toughness of 19.6 GPa, 801 MPa, and 5.31 MPa m 1/2 , respectively.
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DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yujun Ma,Wenliang Wang,Yishuai Fu,Hui Miao,Jiale Huang,Sizhe Han,Yutong Chen
Improving the yield of the target product of monocyclic aromatic hydrocarbons plays an important role in increasing the economic competitiveness of biomass and waste plastics. In this study, a 3D SiC@HZSM-5@CoFe 2 O 4 multifunctional catalyst with high microwave absorptivity and excellent catalysis was successfully fabricated by a “coating-coating” method. Results showed that the obtained SiC@HZSM-5@CoFe 2 O 4 catalyst had a stable porous structure, abundant oxygen vacancy defects, high specific surface area, good dielectric loss performance, and magnetic loss performance. Encouragingly, co-pyrolysis of corncob (CC) and polystyrene (PS) revealed that the catalyst significantly promoted the synergistic effect and improved the selectivity of renewable gasoline-range aromatics (47.2 area %). In addition, finite element simulations indicated that the prepared catalyst with high microwave absorptivity could effectively accelerate the mass and heat transfer, thereby facilitating the cracking and conversion of pyrolysis vapors. This work provides an efficient method for the production of renewable gasoline-range aromatics from the mixture of biomass and waste plastics by microwave-assisted co-pyrolysis (MACP).
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2023
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IF 7.2
Ziyan Li,Da Wang,Jie Chu,Dandan Yang,Yu Yu
Photocatalytic water splitting for hydrogen production is a promising solution to converse solar energy to green fuel. A high-performance photocatalyst system always requires fast surface reaction rate and efficient charge separation. Herein, a novel strategy that photo-assisted silanizing-hydrolyzing method is used to trigger in situ surface hydroxylation selectively on Si atoms of micro-sized 6H-SiC particles. Due to this functionalization, the results show that the silanizing-hydrolyzing process occurs at the Si sites while the C is passivated, leading the Si atoms with electron deficiency property by XPS characterization. It also drives the SiC surface from native hydrophobicity to hydrophilicity , which is benefit to proton absorption and desorption of generated H 2 by FT-IR and contact angle (CA) result. Furthermore, the photo-electron-chemical characterization demonstrate the charge migration and separation of SiC are promoted. The DFT calculation further indicates these surface properties changes are mainly attribute to the surface electron polarization through the hydroxylation, inducing the Si-O spatial charge separation. More importantly, the positive Si atoms exhibit an appropriate proton absorption energy, resulting in easily H 2 desorption from SiC surface. The hydrogen evolution is significantly enhanced by 33 times compared to pristine SiC without any cocatalysts introduced. Our method provides an efficient route to design an environmental-friendly photocatalytic material SiC and construct highly efficient solar energy conversion systems, which can simultaneously facilitate carrier generation, transportation and surface reduction reaction rate.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Xiangsen Xu,Fengye Lyu,Jiahao Chen,Yiqing Zeng,Zhaoxiang Zhong,Feng Zhang,Weihong Xing
In this work, TiO 2 nanocones grown on SiC membrane was used as the support of V 2 O 5 -WO 3 species to prepare V 2 O 5 -WO 3 /TiO 2 @SiC (VWTi(C-X)@SiC) catalytic membrane for dust filtration and NH 3 -SCR denitration. On account of the large specific surface area, abundant surface acid sites and prominent redox property, the optimized VWTi(C-550)@SiC catalytic membrane shows >90% NO removal efficiency at the temperature of 280–360 °C, which are much higher than VWTi(P-550)/SiC catalytic membrane (TiO 2 nanoparticles prepared by traditional vacuum coating titanium sol method was used as the support of V 2 O 5 -WO 3 species, NO conversion <80% at whole tested temperature). Additionally, VWTi(C-550)@SiC displays superior stability during the SO 2 + H 2 O resistance and 300 h long-term test at 300 °C, and exhibits an excellent dust filtration performance (2.5 μm SiO 2 particles interception rate exceeded 99.99%) under all test conditions. More importantly, the structure of nanocones decrease the influence of tensile stresses due to the different thermal expansion coefficients of TiO 2 and SiC membranes, which significantly suppress the fall of VWTi catalyst layer from the surface of SiC during pulse-jet cleaning. Among above results, it can be concluded that the optimized VWTi(C-550)@SiC catalytic membrane shows a prosperous application prospect for the simultaneously dust filtration and NH 3 -SCR denitration of medium–high temperature flue gas .
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DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2023
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IF 6.4
Aolin Xie,Bei Zhang,Yichun Ge,Xiaodong Wang,Ping Xu,Zhirong Feng,Maozhong Yi,Zhe Zhou
To ensure the performance of C/C composites, a surface-modified C/C composite was prepared with a C/C composite as the substrate, one-dimensional SiC as the intermediate, and vertically oriented graphene as the modification material without changing the microstructure or composition of the C/C composites. C/C composite surface modifications were prepared in two steps. Its specific surface area is improved from 0.25 m 2 /g to 10.44 m 2 /g, and the electromagnetic interference shielding efficiency is enhanced from 13.08 dB to 23.86 dB. Different from the C/C composites without surface modification, the electromagnetic interference shielding mechanism of surface-modified C/C composites changed from electromagnetic reflection to the interaction of electromagnetic absorption and reflection. The reason is that the increased specific surface area elongates the transmission paths of the electromagnetic waves by multiple reflections, leading to significantly improved electromagnetic interference shielding efficiency.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Zhengkun Hou,Qiuyan Ding,Xueli Geng,Hong Li,Chang Shu,Xin Gao
For reactive distillation (RD) process limited by the separation efficiency of gas–liquid mass transfer, if the physical size of the alternating operation in reaction and separation can be further reduced, it would greatly promote the efficiency of the RD process. For this purpose, a structured HY@SiC catalytic packing was developed in which the gas–liquid mass transfer separation process and the catalytic reaction occurred simultaneously on its surface. The HY@SiC catalytic packing was used in a pilot-scale column for experimental study on production of cyclohexyl acetate (CA) by RD to verify the performance of the catalytic packing for the first time. Furthermore, a RD model based on the HY@SiC catalytic packing was established based on the reaction kinetics of HY zeolite catalyst obtained in this work. Finally, a novel RD process with double recycle stream for CA production was proposed, which will be optimized design with TAC minimize as the optimization objective based on sequential iterative algorithm.
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2023
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IF 5.7
Yulan Yu,Guanghui Feng,Yujun Jia,Hejun Li
In this work, AlN whisker-reinforced (Zr, Hf)O 2 coating was prepared on SiC coated carbon/carbon composites by sol-gel and plasma spraying methods. Its cyclic ablation resistance was evaluated using an oxyacetylene torch with a heat flux of 2.38 MW/m 2 . After ablation, the coating showed apparently decreased crack sizes and quantity as compared with the one without AlN whisker addition, pointing out its better crack tolerance. Moreover, the coating had a thinner oxidized region based on the linear ablation rate (−0.042 µm/s), greatly lower than that of pure oxide coating (−0.922 µm/s). After detailed observation and characterization, probable protection mechanism was proposed.
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高影响因子
CERAMICS INTERNATIONAL
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2019
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IF 3.45
Heng Zhang,Yong Yang,Bin Liu,Zhengren Huang
SiC-based ceramics with periodic structure were successfully fabricated by extrusion freeforming 3D printing technology and liquid silicon infiltration process. The ceramic slurries containing SiC , carbon black, chopped carbon fiber were firstly prepared with the appropriate viscosity and rheological properties, then were formed by extrusion freeforming 3D printing technology and densified by liquid silicon infiltration sintering successively, to acquire SiC ceramic composites components. The microstructure and morphology of green parts and sintered bodies were observed. Chopped carbon fibers were found to be oriented distribution in SiC ceramic composites parts. The sintered bodies exhibited maximum flexural strength of 300 MPa and sintered linear shrinkage below 2%. The manufacturing method has demonstrated big potential to fabricate ceramic components with personalized complex structure.
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2019
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IF 4.029
Pengju Chen,Peng Xiao,Zhuan Li,Zeyan Liu,Dongmei Pu,Yang Li
A novel cristobalite aluminum phosphate particle ( c -AlPO 4 ) modified SiC whisker toughened mullite coating ( c -AlPO 4 -SiC w -mullite) was prepared on SiC coated carbon fiber reinforced SiC composites (C/SiC) by a new sol-gel method combined with air spraying to improve the oxidation resistance of SiC w -mullite coating. Results show that c -AlPO 4 -SiC w -mullite coatings with 10 and 20 wt.% of c -AlPO 4 exhibited obviously improved oxidation resistance at 1773 K in ambient air for 100 h than SiC w -mullite coating. Moreover, the oxidation resistance of c -AlPO 4 -SiC w -mullite coatings were rapidly declined when the c -AlPO 4 in c -AlPO 4 -SiC w -mullite coating were set to 30 and 40 wt.%. The c -AlPO 4 -SiC w -mullite coating with 20 wt.% of c -AlPO 4 showed most pronounced oxidation resistance, the weight loss rate after the oxidation in ambient air for 210 h was merely 3.00 × 10 −5 g·cm −2 h −1 . The failure of c -AlPO 4 -SiC w -mullite coating with 20 wt.% of c -AlPO 4 was due to the generation of penetrative micro-cracks and micro-holes in the coating, which cannot be self-healed by the silicate glass layer after long time oxidation at 1773 K.
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高影响因子
ACS Applied Materials & Interfaces
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2017
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IF 7.504
Shanliang Chen,Minghui Shang,Lin Wang,Zuobao Yang,Fengmei Gao,Jinju Zheng,Weiyou Yang
Low turn-on fields together with boosted stabilities are recognized as two key factors for pushing forward the implementations of the field emitters in electronic units. In current work, we explored superior flexible field emitters based on single-crystalline 3C-SiC nanowires, which had numbers of sharp edges, as well as corners surrounding the wire body and B dopants. The as-constructed field emitters behaved exceptional field emission (FE) behaviors with ultralow turn-on fields (Eto) of 0.94–0.68 V/μm and current emission fluctuations of ±1.0–3.4%, when subjected to harsh working conditions under different bending cycles, various bending configurations, as well as elevated temperature environments. The sharp edges together with the edges were able to significantly increase the electron emission sites, and the incorporated B dopants could bring a more localized state close to the Fermi level, which rendered the SiC nanowire emitters with low Eto, large field enhancement factor as well as robust current emission stabilities. Current B-doped SiC nanowires could meet all essential requirements for an ideal flexible emitters, which exhibit their promising prospect to be applied in flexible electronic units.
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DOI
PubMed
高影响因子
CARBON
·
2024
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IF 10.5
Guangda Guo,Fang Ye,Laifei Cheng,Yucong Wei,Xu Chen
C f /SiC-ZrC renowned for its outstanding performance as a thermal protectant, has gaining widespread recognition. Recent research on this system has emphasized the development of a cost-effective and reusable version with increased thickness for extended use in thick-walled thermal structural components. Ablation resistance, high strength retention, and high thermal conductivity are crucial for successful aircraft reentry. In this study, a low-cost reactive melt infiltration (RMI) method is developed for preparing dense and high-performance large-thickness C f /SiC-ZrC (L-C f /SiC-ZrC) with a gradient-structured matrix. The use of a fine weave-pierced fabric preform structure enhances both the structural integrity and thermal conductivity of C f /SiC-ZrC in the thickness direction. Simultaneously, the gradient-structured matrix, with appropriate contents of surficial ZrC and SiC exhibits erosion resistance, where the internal core with a high SiC content ensures remarkable strength retention. This unique matrix-structure design is achieved by integrating porous C with a single-stage pore structure and a high degree of graphitization degree, and a Si-Zr alloy with a unique composition. The 20mm thick C f /SiC-ZrC obtained via RMI has a density of 2.79 g/cm 3 with an open porosity of 5.65% and flexural strength of 224.3±5.4 MPa. Under a heat flux of 4.186 MW/m 2 , C f /SiC-ZrC exhibits an ablation rate of −0.004 mm/s after 60 s, demonstrating its resilience against ablation damage. Moreover, the post-ablation strength (166.0±4.4 MPa) exceeds that of reported C f /SiC-ZrC congeners, highlighting the robust load-bearing capability.
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DOI
高影响因子
CORROSION SCIENCE
·
2025
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IF 8.5
Huan Guo,Bingzhu Wang,Ruifeng Li,Cheng Su,Jixiang Dai,Yong She,Yongzhong Zhao,Jianjun Sha
Aiming at forming a stable ablation layer for hafnium-based ultrahigh-temperature ceramics under ablation environment, in this work, the Ta-based ceramic was introduced into the Hf-based ceramic, and the effect of Hf/Ta molar ratios on the ablation response behavior and mechanism of (Hf, Ta)B 2 -(Hf, Ta)C-SiC ceramics was investigated. It was found that the introduction of Ta could form a continuous and dense ablation layer. When Hf/Ta= 0.9:0.1, the ceramic composite presented excellent ablation resistance, and the linear ablation rate was −0.083 μm/s, which was only 5.85 % of that of Hf-based ceramics (HfB 2 -HfC-SiC). The excellent ablation resistance attributed to that the ablation products (Ta 2 O 5 and Hf 6 Ta 2 O 17 ) could strongly bonded to the substrate, which was conducive to enhance the stability of the ablation layer.
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高影响因子
危险品化学品经营许可证（带存储）