SOLID STATE PHENOMENA
·
2018
·
IF 0
Min Wang,Zi Yuan Wang,Ya Jie Yuan,Wei Pan
The 8 wt.% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) are widely used to protect hot superalloy components of gas turbine and jet engine. However, Cracks and pores in the 8YSZ coating would accelerate the oxidation of the bondcoat alloy and the corrosion of 8YSZ topcoat by molten salts and finally result in permanent failure of the TBCs. Hence, in this work, a sol-gel spin-coating method was employed to prepare a dense α-Al2O3 film on the surface of air-plasma-sprayed 8YSZ coatings, in order to block the paths of cracks and pores while keeping the stress tolerance of 8YSZ coatings. The influences of the polyvinylpyrrolidone (PVP) and alumina content of the sol on the microstructure of the α-Al2O3 film were investigated. It is found that a sol with PVP addition amount of 50 mg/mL and alumina solid content of 10% let to the achievement of a compact α-Al2O3 film. The positive results in this work would inspire more efforts to prepare dense films on TBCs and therefore improve their performance under service conditions.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 28
·72354-72367
·
IF 5.8
Zhou Tao,Lu Linghong,Tao Suwan,Ma Yi
In this work, we synthesized activated alumina biochar composites (γ-Al 2 O 3 /BC) by sol–gel method, which improved the problem that the surface charge of γ-Al 2 O 3 was not conducive to the removal of heavy metal cation in a neutral solution, and then explored the feasibility of removing Pb(II) by γ-Al 2 O 3 /BC as well as reusing Pb-laden waste sludge to remove phosphorus (P) and its micro-adsorption mechanisms. The results show that the maximum adsorption capacity of γ-Al 2 O 3 /BC for Pb(II) is 182.48 mg/g, and the removing capacity of recycled Pb-laden slag for P also reaches 87.13 mg/g. It was found that the presence of Pb in the slag makes P removal more effective. In addition, in the process of P removal, the Pb in the slag will not be released, which will not cause secondary pollution to the water. The micro-adsorption mechanism of Pb(II) and P on the composites was investigated by XPS, XRD, and FTIR. It demonstrates that special functional groups such as hydroxy-aluminum, hydroxyl, and carboxyl groups can remove Pb(II) through strong surface complexation and electrostatic attraction. Furthermore, the removal mechanism of P from Pb-laden sludge includes chemisorption and complexation, and the precipitation of P and Pb on the adsorbent surface is the main reason for the removal of P. Therefore, it is feasible to further effectively remove P by using the waste biochar containing Pb. The idea of this paper provides a potential method for the reuse of waste adsorbent.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Xingling Zhao,Xue Zhou,Wanyan Xing,Zhimin Yuan,Kaili Wang,Qihang Zhang,Yulong Shan,Jiani Liu,Lin Ju,Zaiyong Jiang,Hong He
CO is a ubiquitous air pollutant, frequently encountered in the fields of automotive exhaust purification, especial in the cold-start-emission stage. Pt based catalysts are widely used to purify CO into CO 2 owing to their exceptional performance. But they can be few excited to exhibit reasonable catalytic activity due to the low temperature at the cold-start-emission stage. In exhaust gas purification catalysts used by fossil fuel-based vehicles, Al 2 O 3 is used frequently. But there are rarely reports of Pt loaded Al 2 O 3 catalysts achieving feasible activity of CO oxidation at room temperature. Herein, we prepared Cu x Pt y alloy/Al 2 O 3 catalysts (with high penta-coordinated Al 3+ (Al V )), Al V centers as binding sites for Cu 3 Pt 1 alloys on Al 2 O 3 enable the high dispersion and stability of Cu 3 Pt 1 alloy. The adsorption capacity of O 2 and CO molecules on Cu 3 Pt 1 surface are stronger than the case on Pt surface, which may make O 2 and CO molecules more easily activated, making the CO oxidation reaction easier. In addition, the desorption of CO 2 from Cu x Pt y surface is easier compared to that on Pt surface, increasing the frequency of use of active sites there. Therefore, this Cu 3 Pt 1 /Al 2 O 3 catalyst exhibits 100 % conversion of CO with a GHSV of 6×10 3 mL·g −1 cat ·h −1 at room temperature. This work provides a feasible guideline for the design and synthesis of Pt loaded Al 2 O 3 catalysts toward room temperature CO oxidation.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2024
·Vol. 24
·期 6
·2309-2317
·
IF 2.8
Mi Na,Yang Min,Wang Xiaohan,Sun Qian,He Jianzhou,Deng Shaopo,Fan Tingting
Purpose The application of silicon could effectively alleviate Cd contamination in the soil. However, the interaction between silicon and Cd in soils is not well understood. Our research aims to investigate the mechanism of the impact of silicate on the sorption of Cd on metal oxides in soils. Materials and methods Sodium silicate and Cd(II) co-sorption on γ-Al 2 O 3 and goethite at pH 5.5 and 7.5 was studied using a combination of batch sorption experiments, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Results and discussion Silicate enhanced the sorption of Cd(II) onto γ-Al 2 O 3 at pH 5.5 and 7.5. However, the sorption of Cd(II) on goethite at pH 5.5 and 7.5 was only promoted when the silicate concentration reached 1 mmol L −1 . Cadmium(II) enhanced silicate sorption on γ-Al 2 O 3 at pH 5.5 and on goethite at pH 7.5, while it decreased silicate sorption on γ-Al 2 O 3 at pH 7.5 and had no significant effect on goethite at pH 5.5. At pH 5.5, Cd(II) reacted with silicate to generate Cd 2 SiO 4 , and Cd-Si-Al ternary complexes were formed on γ-Al 2 O 3 . At pH 7.5, silicate promoted the formation of Cd(OH) 2 on γ-Al 2 O 3 , which ultimately transformed into CdCO 3 . When silicate concentration reached 1 mmol L −1 , more silicate complexes were formed through the Fe-O-Si bound on goethite at both pH 5.5 and 7.5 to promote the adsorption of Cd(II) owing to its electronegative functional group on the surface of the complex. Conclusions The type of clay minerals, pH, and the presence of silicate all significantly affected Cd sorption. Furthermore, the sorption mechanism of Cd on γ-Al 2 O 3 and goethite in the presence of silicate has been elucidated. The above findings improve our understanding of the mechanism for immobilizing Cd in soils using silicon-containing materials.
研究领域:
土壤科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Weichao Wang,Gu Liu,Liuying Wang,Chaoqun Ge,Long Wang,Bin Wang,Jie Huang
The advancement of absorption materials and coating preparation technology is crucial to address the challenges posed by electromagnetic interference and pollution in high-temperature extreme environments. Here, by using a granulation and plasma spraying strategy, we successfully fabricated a series of La 0.8 Sr 0.2 MnO 3 /Al 2 O 3 –13%TiO 2 (LSMO/AT13) high-temperature microwave absorption coatings that have excellent dielectric properties and extremely thermal stability. The results showed that the LSMO/AT13 coatings exhibited remarkable oxidation resistance , withstanding high-temperature aerobic environments of up to 1000 °C. Based on the temperature-dependent permittivity of the coatings, the establishment process of polarization and the transformation of loss mechanism were observed and explained. With the increase of temperature, the main dielectric loss mechanism of the coatings transitions from polarization loss to conductive loss. Thanks to the coordinated effects of impedance and loss, the coatings are capable of effectively absorbing microwave over a wide temperature range. When the LSMO content was 30 wt% and the thickness was 1.9 mm, the effective bandwidth ranged from 1.7 GHz to 2.4 GHz at temperatures below 773 K. This study demonstrates the promising application of LSMO/AT13 microwave absorption coatings for ultra-high temperature environment, and provides a reference for the design and optimization of high-temperature microwave absorption coatings.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2015
·
IF 1.955
Chang Su,Yu Li,Yue He,Li Liu,Xuesong Wang,Lili Liu
In this work, pure and Al 2 O 3 -doped α-Fe 2 O 3 nanotubes were synthesized by a simple single-capillary electrospinning technology and followed calcination treatment. The morphologies and crystal structures of the as-prepared samples were characterized by scanning electron microscopy and X-ray diffraction, respectively. The research of the samples gas sensing properties demonstrates that the ethanol sensing properties of α-Fe 2 O 3 nanotubes are enhanced by doping Al 2 O 3 , remarkably. The response value of Al 2 O 3 -doped α-Fe2O3 nanotubes to 50 ppm ethanol is 41.8 at the operating temperature 240 °C, which is much higher than that of pure α-Fe2O3 nanotubes (response value is 4). And the lowest detection limit is 300 ppb, to which the response value is about 2. The response and recovery times are about 20 and 60 s–50 ppm ethanol, respectively. In addition, the Al 2 O 3 -doped α-Fe2O3 nanotubes possess good selectivity and long-term stability.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2018
·Vol. 42
·期 11
·3870-3876
·
IF 1.5
Ji Ruo-Nan,Liu Chen-Xu,Zhang Jin,Zhang Shu-Guang,Zhang Le,Lian Yong
Al 2 O 3 /polytetrafluoroethylene (PTFE) composite coating was prepared on titanium alloy by cathode plasma electrolytic deposition (CPED) and impregnation method, to improve the hydrophobicity and tribological properties. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis of the coating indicate that PTFE penetrates into the interior of the coating and is well bonded to titanium alloy substrate by cross-linking with Al 2 O 3 ceramic coating. The contact angles were measured by contact angle measurement, and the tribological properties of the composite coating were evaluated by sliding wear test. The surface of the composite coating is found to possess good hydrophobicity with a water contact angle of 140°. The results also indicate an improved tribological properties of Al 2 O 3 /PTFE composite coating at room temperature with a steady friction coefficient as low as 0.05. The self-lubricating anti-wear composite coating is expected to solve fouling problems and poor wear resistance of titanium alloys.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Yingnan Dong,Yumeng Jia,Kenan Xu,Xu Sun,Jing Wang,Zhongxiang Shi,Yanchen Liu
In order to expand the multi-scene application of rare earth doped luminescent materials in the field of blue light illumination, a series of Ce 3+ doped Na-β″-Al 2 O 3 phosphors were prepared by solid-state method with Na-β″-Al 2 O 3 as matrix. The crystal structure, micro-morphology, optical properties and thermal stability were investigated systematically. The results show that the activated ion Ce 3+ in the prepared Na-β″-Al 2 O 3 : x Ce 3+ phosphor replaces the Al 3+ (CN = 6) lattice in the crystal, and with a outstanding blue light emission. In addition, the thermal stability of Na-β″-Al 2 O 3 : 0.05Ce 3+ phosphor is analyzed by variable temperature spectrum, and its luminescence intensity at 573K can reach 71.55 % at room temperature. Finally, Na-β″-Al 2 O 3 : 0.05Ce 3+ phosphors are packaged with 330 nm n-UV LED chips to obtain high quality blue LED devices. With its high color rendering index (81.60), low color temperature (2886 K) and good color consistency, it provides a theoretical basis for the application of Na-β″-Al 2 O 3 -based phosphors in blue LED devices, and makes it show great application potential in the field of solid-state blue spectral lighting.
研究领域:
材料科学
·
固体化学
·
发光材料
·
照明工程
·
无机功能材料
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2023
·Vol. 10
·期 11
·3149-3155
·
IF 7.3
Hang Zhang,Kang Liu,Yingkang Chen,Xiaojian Wang,Hongmei Li,Junwei Fu,Liyuan Chai,Zhang Lin,Min Liu
CF4 is the most emitted perfluorocarbon (PFC) and possesses a great global warming potential (GWP) of 7390 with a lifetime of 50 000 years. Catalytic hydrolysis is a promising method for reducing CF4 emissions; however, the HF product can easily poison the catalyst, resulting in poor stability. In this study, a strategy for resisting HF corrosion by enhancing the order of aluminum-oxide polyhedron is originally demonstrated. HF corrosion experiments indicated that the Al2O3 catalysts with a higher order of aluminum-oxide polyhedron exhibited better resistance to HF corrosion (HF corrosion reaction rate k2, γ-Al2O3: 1.34 × 10−3, θ-Al2O3: 1.90 × 10−5, and α-Al2O3: 1.30 × 10−5). The obtained θ-Al2O3 achieved a lifetime of 100 h with 100% decomposition of CF4 at 750 °C, which is ∼20 times that of the γ-Al2O3 catalyst, and α-Al2O3 was inactive for CF4 decomposition. Theoretical calculations also demonstrated that θ-Al2O3 had lower adsorption and higher reaction barriers with HF than those of γ-Al2O3, proving the high stability of θ-Al2O3. This study provides a new inspiration for the development of efficient and stable CF4 decomposition catalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 11
·827
·
IF 3.8
Yumeng Song,Ping Chen,Hui Lou,Xiaoming Zheng,Xiangen Song
In this work, the highly efficient hydrogenation of guaiacol catalyzed by ruthenium supported on Al2O3-TiO2(Ru/Al2Ti1) at very mild conditions was carried out. At temperatures as low as 25 °C and 2 MPa H2, about 60% of guaiacol could be converted to 2-methoxycyclohexanol (MCH) with a selectivity as high as 94% on the Ru/Al2Ti1catalyst with an appropriate hydrogen pressure. At temperatures above 50 °C, almost all of the guaiacol could be converted with the catalyst of Ru/Al2Ti1, mainly into hydrogenated products such as MCH. The surprisingly efficient hydrogenation of guaiacol at low temperatures was most likely due to the ability of Ru particles loaded on the specific complex metal oxide carriers, particularly the reduction of the edge effect of Ru, to activate phenyl and hydrogen and reduce the competition of the dimethoxy process. These findings about the high activity of the Ru/Al2Ti1catalyst at nearly room temperature may be helpful to upgrading the industrial process of the pyrolysis bio-oils.
研究领域:
催化化学
·
可再生能源
·
工业化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 89
·48317-48321
·
IF 3.708
Yun Yu,Weimin Hou,Xuebing Hu,Yang Yu,Le Mi,Lixin Song
A novel superhydrophobic Al2O3 microfiltration membrane was prepared by the layer-by-layer assembly of TiO2 coating with subsequent fluorination grafting surface treatment by 1H,1H,2H,2H-perfluorodecyltriethoxysilane. The influence of surface morphology on membrane superhydrophobicity, pore size diameter distributions and pure water permeability of the different membranes were studied. By optimizing the grafting parameters, a needle-like surface of grafted TiO2-coated Al2O3 membrane with a water contact angle of 169.5° was obtained. The pure water permeability of different membranes varied from 100 l m−2 h−1 bar−1 before grafting to 3–5 l m−2 h−1 bar−1 after grafting, and the grafted superhydrophobic membrane showed excellent water repellence. The novel superhydrophobic membrane is shown to be promising for liquid–liquid and gas–liquid separation.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Qinglian Wang,Huaiyu Wang,Jintian Zhong,Zhaoyang Qi,Jie Chen,Changshen Ye,Ting Qiu
Deep desulfurization of fuel oil is always a highly challenging issue. In this work, ZrXPTA material was obtained by directly combining the ZrIV active site with PTA, and it was found that ZrXPTA has excellent catalytic activity in the oxidative desulfurization (ODS) process. Further, ZrXPTA was loaded on γ-Al2O3 by the two-step impregnation to obtain a granular Al2O3@ZrXPTA composite. The successful synthesis of the material was verified by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and N2 adsorption–desorption. The results show that Al2O3@ZrXPTA maintains the high ODS activity of ZrXPTA and realizes the rapid and complete removal of dibenzothiophene under mild reaction conditions (T = 40 °C, O/S = 4, t = 30 min). The mechanism study shows that the ODS activity of Al2O3@ZrXPTA is wholly derived from the counterpart of ZrXPTA, which benefits from the synergistic catalytic effect between the ZrIV active site and PTA. The direct binding of these two active sites makes the synergistic effect fully exerted. In addition, the recovery of Al2O3@ZrXPTA can be easily realized by simple filtration or decantation, and no significant activity loss was observed after five times recycling. Therefore, Al2O3@ZrXPTA has high ODS activity, high catalytic stability, and great potential as an ODS catalyst in practical applications.
研究领域:
化学工程
·
催化材料科学
✓ 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）