SURFACE & COATINGS TECHNOLOGY
·
2022
·
IF 4.865
Jingjing Ma,Chaoyang Cai,Jiawei Xie,Wenming Guo,Hang Qin,Jingxiong Liu,Wen Xie,Pengzhao Gao,Hanning Xiao
The low coefficient of thermal expansion (CTE) coating was designed for SiC oxidation-resistant applications by using Al 2 O 3 and LiAlSiO 4 as positive and negative expansion materials. The CTE value, relative density and flexural strength of LiAlSiO 4 -Al 2 O 3 coating were characterized. The effect of LiAlSiO 4 -Al 2 O 3 coating on the oxidation resistance and flexural strength of SiC substrate was systematically studied by cyclic oxidation tests at 1400 °C. Results showed that LiAlSiO 4 -Al 2 O 3 coating with 20 wt% LiAlSiO 4 exhibited optimal properties, featuring the excellent relative density of 93.14 %, appropriate CTE of 5.815 × 10 −6 /°C, and high flexural strength of 56.35 MPa. The weight gain of the SiC with LiAlSiO 4 -Al 2 O 3 coating was 0.49 % after 100 h of oxidation, much lower than 2.25 % of bare SiC substrate, indicating that LiAlSiO 4 -Al 2 O 3 coating effectively hindered the diffusion of oxygen and improved the oxidation resistance of SiC substrate. Moreover, the dense coating blunted defects on the SiC substrate surface, which maintained the high strength of the coated SiC after long periods of oxidation.
研究领域:
材料科学
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涂层技术
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产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 18
·4391
·
IF 4.2
Kaihui Hua,Zhijing Wu,Weijie Chen,Xiuan Xi,Xiaobing Chen,Shuyan Yang,Pinhai Gao,Yu Zheng
Titanium dioxide (TiO2) is widely employed in the catalytic degradation of wastewater, owing to its robust stability, superior photocatalytic efficiency, and cost-effectiveness. Nonetheless, isolating the fine particulate photocatalysts from the solution post-reaction poses a significant challenge in practical photocatalytic processes. Furthermore, these particles have a tendency to agglomerate into larger clusters, which diminishes their stability. To address this issue, the present study has developed Al2O3–SiO2–TiO2composite semiconductor porous ceramics and has systematically explored the influence of Al2O3and SiO2on the structure and properties of TiO2porous ceramics. The findings reveal that the incorporation of Al2O3augments the open porosity of the ceramics and inhibits the aggregation of TiO2, thereby increasing the catalytic site and improving the light absorption capacity. On the other hand, the addition of SiO2enhances the bending strength of the ceramics and inhibits the conversion of anatase to rutile, thereby further enhancing its photocatalytic activity. Consequently, at an optimal composition of 55 wt.% Al2O3, 40 wt.% TiO2, and 5 wt.% SiO2, the resulting porous ceramics exhibit a methylene blue removal rate of 91.50%, and even after undergoing five cycles of testing, their catalytic efficiency remains approximately 83.82%. These outcomes underscore the exceptional photocatalytic degradation efficiency, recyclability, and reusability of the Al2O3–SiO2–TiO2porous ceramics, suggesting their substantial potential for application in the treatment of dye wastewater, especially for the removal of methylene blue.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jihui Yao,Zhikang Xu,Shuo Cheng,Yuanyuan Yue,Haibo Zhu
The use of dodecahydro- N -ethylcarbazole in hydrogen storage for liquid organic hydrogen carrier systems holds potential for achieving large-scale application. In order to investigate the relationship between dodecahydro- N -ethylcarbazole dehydrogenation performance and Pt particles size, a series of monometallic Pt/Al 2 O 3 catalysts with different Pt particles size from 0.70 nm to 5.12 nm were controlled synthesized by a simple impregnation method. The obtained catalysts are systematically characterized via XRD, 27 Al MAS NMR, SEM-EDS, TEM, N 2 -adsorption, CO-IR, H 2 -TPR and NH 3 -TPD analyses, which provide essential micro-structure of these catalysts. The dehydrogenation of dodecahydro- N -ethylcarbazole over Pt/Al 2 O 3 is a typical consecutive reaction, which follows a reaction sequence of dodecahydro- N -ethylcarbazole → octahydro- N -ethylcarbazole → tetrahydro- N -ethylcarbazole → N -ethylcarbazole. These dehydrogenation steps are quite sensitive to the Pt particle size. Large Pt particle can greatly enhance the reaction rates in octahydro- N -ethylcarbazole → tetrahydro- N -ethylcarbazole and tetrahydro- N -ethylcarbazole → N -ethylcarbazole steps. However, these two steps are difficult to take place in small Pt particles. The high performance of large Pt particle in dehydrogenation can be ascribed to its highly exposed (1 1 1) crystal face. The optimized catalyst Pt 5.0 /γ-Al 2 O 3 with Pt average size of 4.63 nm demonstrated exceptional performance in dodecahydro- N -ethylcarbazole dehydrogenation at 180 °C and 101 kPa, and the dodecahydro- N -ethylcarbazole conversion of 100 %, N -ethylcarbazole selectivity of 96.44 % and dehydrogenation efficiency of 98.73 % can be achieved. These results provide valuable insights for the development of efficient metal-based catalysts for liquid organic hydrogen carriers hydrogen storage system.
研究领域:
催化化学
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能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2024
·
IF 3.4
Yang Zhang,Qizhuang Zou,Ruiqi Fang,Hua Tan,Hongbing Ji,Yingwei Li
Yolk-shell nanoreactors feature numbers of advantages in promoting catalytic performance. This work demonstrates the fabrication of yolk-shell Fe 3 O 4 @SiO 2 /Al 2 O 3 - T ( T = 500–900 °C) from metal-organic framework. Characterizations indicate the Fe 3 O 4 yolk and SiO 2 /Al 2 O 3 shell of the obtained nanoreactors. Fe 3 O 4 @SiO 2 /Al 2 O 3 –800 showed excellent performance in furfural acetalization to 2-(dimethoxymethyl)furan, achieving a 97% yield at 60 °C, atmospheric pressure within 5 h. Control experiments reveal the high reactivity of Fe 3 O 4 yolks for furfural acetalization, and acidic Al species are favorable for reactivity promotion. Besides, porous SiO 2 /Al 2 O 3 shells facilitate mass transfer and increase the accessibility of active sites, also contribute to the high performance and stability.
研究领域:
化学工程
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纳米材料科学
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2017
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IF 2.942
Yuehua Sun,Chaoqun Peng,Xiaofeng Wang,Richu Wang,Junliang Yang,Dou Zhang
Al 2 O 3 polyelectrolyte suspensions containing PAA-PEI complexes have been used for direct ink writing to fabricate complex 3D structures with micro-sized feature. Zeta potential and rheological behavior of the Al 2 O 3 polyelectrolyte suspensions were investigated. The isoelectric point of Al 2 O 3 particles shifts from alkaline region to acidic region as the [COOH]:[NH x ] ratio increases from 0.12 to 3. The rheological results reveal that the 40 vol% Al 2 O 3 suspension with [COOH]:[NH x ] ratio of 0.3 and 15 mg/mL methylcellulose at pH 10 is the optimal suspension for direct ink writing, due to its good shear thinning and viscoelastic behavior . The filament in lattice structure prepared using this polyelectrolyte suspension can maintain its original shape with little spreading. In the micrograph of sample sintered at 1600 °C for 2 h, the uniform size of grains indicates that the structure is fully sintered under this sintering condition.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Theranostics
·
2018
·
IF 8.537
Wenfei Chen,Ming Qin,Xiaoyan Chen,Qin Wang,Zhirong Zhang,Xun Sun
Photothermal therapy (PTT) can be an effective antitumor therapy, but it may not completely eliminate tumor cells, leading to the risk of recurrence or metastasis. Here we describe nanocarriers that allow combination therapy involving PTT and immunotherapy. Nanocarriers are prepared by coating Al 2 O 3 nanoparticles with non-toxic, biodegradable polydopamine, which shows high photothermal efficiency. A near-infrared laser irradiation can kill the majority of tumor tissues, resulting in the release of tumor-associated antigens. The Al 2 O 3 within the nanoparticles, together with CpG, acts as an adjuvant to trigger robust cell-mediated immune responses that can help eliminate the residual tumor cells and reduce the risk of tumor recurrence. Methods: The characteristics and photothermal performance of polydopamine-coated Al 2 O 3 nanoparticles were examined after one-step preparation. Then we studied their internalization, photothermal toxicity and immunostimulatory activity in vitro . For in vivo experiments, these nanocarriers were injected directly into B16F10 melanoma allografts in mice to ensure specific localization. After photothermal irradiation on day 0, mice were subcutaneously injected with CpG adjuvant on day 1, 3 and 5. Tumor volumes and number of living mice were recorded every two days. Moreover, various immune responses induced by our combined therapy were tested for mechanism research. Results: 50% of mice after our combined treatment successfully achieved the goal of tumor eradication, and survived for 120 days, which was the end point of the experiment. Mechanism studies demonstrated the combined therapy efficiently led to dendritic cell maturation, resulting in the secretion of antibodies and cytokines as well as the proliferation of splenocytes and lymphocytes for anti-tumor immunotherapy. Conclusion: Taken together, these results demonstrated the promise of our combined photothermal therapy and immunotherapy for tumor shrinkage, which merited further research.
研究领域:
肿瘤学
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纳米医学
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免疫学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2023
·Vol. 34
·期 7
·987-991
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IF 1.4
Su Xiao-Ping,Zhao Le,Wang Xiang-Tong,Wang Zhao,Wang Zhi-Chao,Shen Tao,Zhang Ping
Different Al2O3 carriers were synthesized by co-precipitation and sol-gel method. From them, 4%NiO-20%MoO3/Al2O3 catalysts were prepared by incipient wetness impregnation. The catalysts were characterized by X-ray diffraction analysis (XRD), N2 adsorption-desorption, NH3 temperature programmed desorption (TPD) and H2-temperature programmed reduction (TPR) and subsequently used for selective hydrogenation of naphthalene to high-value tetralin. The results showed that Ni-Mo/so-ge Al2O3 (900) exhibited better catalytic performance than Ni Mo/commercial Al2O3, achieving 99.56% naphthalene conversion and 99.43% tetralin selectivity.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Xiaolei Sun,Meiyi Jing,Hong Dong,Wenhe Xie,Feng Luo
Transition metal oxides are said to have the ability to enhance the gravimetric capacity of lithium-ion batteries by two or three times that of current state-of-the-art graphite anodes. Recent reports have demonstrated that the combined utilization of structural architecture and surface modification is an attractive strategy to improve lithium storage capability. In this study, novel CuO-ZnO@Al 2 O 3 submicroflakes were prepared by magnetron sputtering deposition of Cu-Zn alloy films on a removable sacrificial substrate, followed by a facile thermal oxidation treatment and Al 2 O 3 coating procedure by particle atomic layer deposition. They combine the advantages of CuO-ZnO submicroflakes, such as high lithium storage capability and fast lithium ion transportation, and Al 2 O 3 nano-coating with effective protection of the electrode interface during cycling. When utilized as anode materials for LIBs, the CuO-ZnO@Al 2 O 3 submicroflakes exhibit superior specific capacity, enhanced cycling stability, and outstanding rate capability compared with pristine CuO-ZnO submicroflakes, commercial CuO and ZnO powders. The CuO-ZnO@Al 2 O 3 submicroflakes electrodes deliver a high reversible capacity of 814 mAh g −1 at a current density of 50 mA g −1 , and still maintain a moderate capacity of 447 mAh g −1 at a high current density of 1000 mA g −1 . Pairing with a commercial LiFePO 4 cathode, full cell shows high capacity retention and stable cycling performance, suggesting the feasibility of the CuO-ZnO@Al 2 O 3 submicroflakes in practical energy storage applications. In addition, our findings also provide a clear proof-of-concept of the surface coating technique, which might be applied widely to other materials and devices where nano-coating produces desirable properties.
研究领域:
材料科学
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能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2023
·
IF 6.2
Zixuan Zhao,Can Zou,E Zhou,Qing Liu,Kai Chen,Xingfu Wang,Longfei He,Fangliang Gao,Shuti Li
Interface engineering is an effective way to improve the performance of graphene-based photodetectors . Here, a graphene/GaAs heterojunction photodetector is fabricated, and when inserting an Al 2 O 3 tunneling layer, its performance is improved through direct tunneling (DT) and Fowler-Nordheim tunneling (FNT). According to the experimental results, it is found that the thickness of the tunneling layer has a great influence on the performance of the photodetector. Compared with graphene/GaAs photodetector, the performance of graphene/Al 2 O 3 (2 nm)/GaAs photodetector is significantly improved with the responsivity, detectivity, and external quantum efficiency value of 0.80 A/W, 3.02 × 10 11 Jones and 306% under 1 mW/cm 2 light intensity at 2 V bias. Meanwhile, fast response is also observed (rise/decay time of 3 ms/8.6 ms). The improvement of the photodetector's performance in this work is mainly attributed to the effective modification of the interface state by the Al 2 O 3 tunneling layer and the effect of the two tunneling mechanisms based on DT and FNT.
研究领域:
材料科学
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光电探测器
·
界面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2024
·
IF 5.8
Wenjie Zhu,Yuwei Ren,Minghang Li,Yichun Bi,Ce Zheng,Xiaoqiang Li
Ti 3 SiC 2 MAX phase with a purity of up to 98 vol%, comparable to the purity of commercial Ti 3 SiC 2 prepared by Hot Pressing (HP), was synthesized by Reactive Melt Infiltration (RMI) in this work, overcoming the inherent shortcoming of RMI products' poor purity. Compared with HP Ti 3 SiC 2 , the lower preparation temperature and pressure-free fabrication of high-purity RMI Ti 3 SiC 2 make it promising for applications in the Ceramic Matrix Composites (CMCs), especially for complex shaped CMCs parts. This work systematically studied the generation mechanism of Ti 3 SiC 2 with the help of κ-Al 2 O 3 during the RMI process, which enables the successful production of high-purity Ti 3 SiC 2 . The toughening mechanism of Ti 3 SiC 2 in Ti 3 SiC 2 composites was also characterized and analyzed. This work attempts to provide a new idea for introducing high-purity ceramic phase into CMCs by RMI process.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2024
·Vol. 13
·期 1
·15
·
IF 2.8
Bo Zhang,Peiyu Yao,Fei Li,Li Pan,Wuwan Xiong,Yang Zhang,Xiang Li
Hydrogen production through the catalytic pyrolysis of low-value organic solid waste offers a promising low-carbon and environmentally friendly pathway. However, the design of efficient hydrogen-producing catalysts remains a significant challenge. Herein, NiO/Al2O3as a catalyst precursor was utilized to investigate the effects of reduction temperature gradients (300–800 °C) on the distribution of three-phase products and the composition of gaseous products during the pyrolysis of waste textiles. Compared to unreduced NiO/Al2O3, increasing the reduction temperature (300–700 °C) led to a gradual decrease in liquid-phase products and a notable increase in gas-phase products, with the latter rising by 10.59% at 700 °C. Most strikingly, hydrogen gas production increased by 6.42% under the same conditions. Multi-characterization analyses, including XRD, TEM, and H2-TPR, revealed significant aggregation of highly dispersed Ni species in NiO/Al2O3at higher reduction temperatures. The emergence of XRD characteristic peaks and the (111) crystal face of metallic Ni (Ni0) became apparent at 700 °C. More importantly, the XPS test inferred that the increasement of hydrogen-rich gas production was ascribed to the appropriate Ni0/Ni2+ratio, and the highest hydrogen yield of 41.50% was achieved as the Ni0/Ni2+ratio reached about 1.57. This work not only provides an effective solution for the consumption of waste textiles, but also converts it into high value-added hydrogen-rich gas.
研究领域:
能源科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Shaoliang Zhu,Bingtao Zhao,Yaxin Su
High-efficiency and cost-effective adsorbents are crucial to dry capture of carbon dioxide (CO 2 ). The polyethyleneimine (PEI) was co-impregnated with tetraethylenepentamine (TEPA) on γ-alumina (Al 2 O 3 ) to synthesize the adsorbent and enhance the capture process. The influence of amine loading and operating parameters on CO 2 adsorption was investigated, and the process parameters were modeled. The results depict that the optimal loading is 50 % when functionalized either PEI or TEPA individually, which is 3.7 and 4.6 times higher than γ–Al 2 O 3 . The CO 2 capacity of γ–Al 2 O 3 functionalized with multiple amines (30 %PEI+20 %TEPA) is 2.65 mmol/g, due to the synergies of the two amines to increase the chance of CO 2 binding to the sites. Regeneration performance illustrates that the adsorbent remains at 90.2 % of the initial capacity after seven tests. The maximal capacity of 2.70 mmol/g occurs at 70 °C. Modeling results indicate the kinetics can be evaluated by the Avrami model (R 2 > 0.990) with the activation energy of 5.65 kJ/mol. The process is controlled by physical–chemical adsorption, influenced by intraparticle diffusion, as described by the deactivation model. Finally, a comparison and assessment were conducted for their techno-economic performances, and the pathway to applications was also proposed in engineering practice.
研究领域:
化学工程
·
环境科学
✓ 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）