查找使用阿拉丁产品的科研文献

Formation and Properties of Superhydrophobic Al Coatings on Steel

Yunyun Ge,Jiangbo Cheng,Xiuyu Wang,Lin Xue,ShuaiShuai Zhu,Baosen Zhang,Sheng Hong,Yuping Wu,Xiancheng Zhang,Xiu-Bing Liang

Thermal sprayed aluminum coatings are widely scalable to corrosion protection of the offshore steel structure. However, the corrosion rate of the Al coating increases considerably due to the severe marine environment. It has remained a challenge to improve the corrosion resistance and protective ability of Al coatings. The superhydrophobic surface provides a potential way to improve the corrosion resistance of metal materials. Hence, the development of superhydrophobic Al coatings with superior corrosion resistance is of great interest. In this work, the feasibility of the preparation of superhydrophobic Al coatings on a steel substrate was explored. First, Al coatings were prepared onto the steel substrate by the arc-spraying process, followed by ultrasonic etching with 0.1 M NaOH solution, and afterward passivated using 1% fluorosilanes. The effects of the etching time on morphology, contact angle, and corrosion resistance of the Al coatings were evaluated. The schematic model of the fluorosilane passivation process on the Al coating surface was provided. The micro/nanoscale surface structure of the low-surface-energy fluorosilanes promotes the wetting angle of 153.4° and a rolling angle to 6.6°, denoting the superhydrophobic properties. The superhydrophobic Al coating surface displays excellent self-cleaning performance due to its weak adhesion to water droplets. The corrosion current density of the superhydrophobic Al coating (1.36 × 10–8 A cm–2) is 2 orders of magnitude lower than that of the as-sprayed Al coating (1.18 × 10–6 A cm–2). Similarly, the charge-transfer resistance is found to be 12 times larger for the superhydrophobic Al coating and the corresponding corrosion inhibition efficiency reaches 98.9%. The superhydrophobic Al coating displays superior corrosion resistance and promising applications in a marine corrosion environment.

High-Quality Cu-Al Nanocrystals for Enhanced CO2 Electroreduction

Guangbo Wang,Hao Zhang,Jiahao Yang,Zeyi Lu,Wenqiong Li,Yanmei Tang,Yun He,Xiaoguang Liang,Xingyuan San,Vellaisamy A. L. Roy

In the quest to optimise the catalytic activity and selectivity of the CO2 reduction reaction (CO2 RR), various imperfections-such as defects, grain boundaries, and vacancies-pose significant challenges. In a groundbreaking approach, we present the synthesis of well-structured CuAl nanocrystals featuring a preferential (111) crystal facet, a first in the field. This innovative structure not only enhances selectivity but also establishes a clear structure-activity relationship for CO2 RR. The unique properties of CuAl nanocrystals stem from their ability to finely control bonding interactions with CO2 RR intermediates, driven by the synergistic effects of the (111) facet. Utilising a straightforward chemical vapour deposition (CVD) method, we produce these nanocrystals, revealing the atomic distribution of Cu and Al on this dominant surface, which crucially influences CO2 RR performance. Among them, Cu96Al4 achieves the highest Faraday efficiency (FE) for HCOOH (77.71%) and CO (18.01%), attributed to the synergistic effects of Cu and Al arising from the optimal d-band centre of Cu active sites and the strong electron-donating ability of Al. This interaction facilitates the electron transfer from Cu to *COOH, resulting in a high FE for C1 product. Our findings pave the way for advanced catalytic designs that can significantly elevate CO2 conversion efficiencies.

A polymeric al/La chloride coagulant for fluoride removal

Lin Zizeng,Wang Gu,Wang Chun

A new type of composite coagulant, polyaluminum lanthanum chloride (PALC), was prepared using AlCl 3 ·6H 2 O and LaCl 3 ·7H 2 O as the main raw materials. The optimal preparation conditions were determined with the removal rate of fluoride ions as the evaluation index, which were a basicity degree B value of 1.00 and an Al/La molar ratio of 10:5. Under the optimal preparation conditions, the particle size of PALC was 121 nm and the Zeta potential was 35.3 mV, significantly larger than the corresponding values of 21 nm and 6.9 mV for polyaluminum chloride (PAC), indicating an enhanced particle size and positive charge carrying capacity. The FTIR spectrum of PALC exhibits a La–O-related band at ∼846 cm −1 and a weak feature near 1041 cm −1 attributed to metal–oxygen/metal–hydroxyl (M–O(H)) vibrations in the hydrolyzed Al/La framework, suggesting La incorporation and structural perturbation of the Al-hydroxo polymer network. EDS analysis indicated that the weight percentages of La and Al in PALC were 21.51% and 9.95%, respectively, suggesting that La ions had stronger competitiveness and preferentially combined with –OH to form high-polymer lanthanide products.SEM-EDS analysis suggested a heterogeneous hierarchical distribution of La and Al within the PALC aggregates, with La-enriched inner regions and Al-enriched outer regions. Characterizations by DLS, FTIR, SEM, and EDS demonstrated the successful preparation of PALC, which exhibited stronger adsorption bridging and electro-neutralization capabilities.

Sustainable Regeneration of Spent LiFePO4 Cathode with Al-Doping

Chengyan Huang,Tianshun Yao,Hengyi Zhu,Yibing Liu,Haiou Zhang,Hongxia Han

With the popularity of electric vehicles, the number of used lithium iron phosphate (LiFePO 4 , LFP) batteries has increased significantly, and failure to properly dispose of these end-of-life power batteries will cause serious harm to the environment. In this study, an environmentally friendly and efficient solid-phase method is proposed to regenerate spent LFP cathode materials. In this method, the crystal structure of LFP cathode materials is restored by supplementing lithium using a lithium source, Fe 3 + impurities in LFP are reduced using glucose, and the regenerated materials are carbon coated. In addition, Al 3 + is introduced to dope the regenerated LFP to further enhance its repair effect. The test results show that the Al 3 + -doped regenerated LFP material has a low electrochemical impedance, and its discharge-specific capacity reaches 148.59 mAh g −1 at a 0.05 C multiplication rate, which is about 93.38% of the discharge-specific capacity of the new LFP (N-LFP). The capacity retention rate reaches 89.02% after 500 cycles at 1 C multiplication rate. These data indicate that the doped and regenerated LFP material exhibits an excellent capacity recovery rate and cycling stability. This study provides a new route for the recycling of waste LFP cathode materials.

Electrophoretic deposition and characterization of nano-Al/Fe2O3 thermites

Daixiong Zhang,Xueming Li,Bo Qin,Chuan Lai,Xiaogang Guo

Nano-Al/Fe 2 O 3 thermites were successfully prepared as film by a novel electrophoretic deposition (EPD) method. The micromorphology investigations demonstrate that electrophoretic deposition of nano-Al/Fe 2 O 3 thermites offer a feasible route for the formation of the interfacial contact between nano-Al and nano-Fe 2 O 3 particles in the film is nanoscaled. Linear relationship studies showed that a coefficient of proportionality between mass ratio in deposited films and that in suspension was observed for EPD of nano-Al/Fe 2 O 3 thermite. The optimum velocity in combustion investigations was found to correspond to mass ratio in deposited thermite. The EPD method is promising for preparation of nano-Al/Fe 2 O 3 thermite with excellent combustion performance.

The surface behaviour of an Al-Li7La3Zr2O12 solid electrolyte

Lixiong Bai,Wendong Xue,Yan Li,Xiaoguang Liu,Yong Li,Jialin Sun

The surface structure and interfacial behaviour of Al-Li 7 La 3 Zr 2 O 12 were studied by Rietveld refinement of X-Ray Diffraction(XRD), Raman Spectra and Electrochemical Impedance Spectroscopy . It was found that Li + with different amount in Li-O octahedra on the surface of Al-Li 7 La 3 Zr 2 O 12 affects the electrochemical behaviour of the material. The increase of Li + occupancy in octahedral site can reduce the activation energy on the surface and improve the ionic conductivity of the material.

MIL-53(Al) catalytic synthesis of poly(ethylene terephthalate)

WANG JI,WANG QINGYIN,WANG GONGYING

Poly(ethylene terephthalate) (PET) is one of the world's five major engineering plastics and is widely used in various fields. At present, the main catalysts used in the synthesis of PET are antimony, titanium, and aluminum metal compounds. Among them, antimony-based catalysts are poisonous and the titanium-based catalyst products are relatively yellow in hue. The aluminum-based catalyst has the advantages of low price and environmental friendliness, but current research shows that the organoaluminum catalyst has the problem of hydrolysis, and MIL-53 (Al) has good stability and will not affect the environment, so we add a catalyst before the esterification reaction, and uses thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and N2 low-temperature physical adsorption characterizes the thermal stability and structure of MIL-53(Al). At the same time, the effects of different content, polycondensation time, before and after activation and polycondensation temperature on the properties of PET were investigated. The research results show that when the molar content of catalyst is 0.05% and the reaction temperature is 280 oC for 150 min, the product obtained is relatively excellent. The catalytic activity has almost no effect before and after activation, indicating that the polycondensation reaction is carried out on the surface of the catalyst. Therefore, MIL-53 (Al) has great potential in PET industrial catalysis.

A Polyurethane Organic Framework for Flexible Al–Air Batteries

Songmao Zhang,Yichun Wang,Yawen Li,Manhui Wei,Keliang Wang

Flexible Al–air batteries with hydrogels are regarded as a promising power source owing to their high specific capacity, their high ionic conductivity, and having no leakage. However, the mechanical properties of the hydrogels remain unresolved. Here, we present a polyurethane organic framework (POF) employing a polyurethane skeleton as an internal support for poly(acrylic acid) (PAA) hydrogel, where the POF can exhibit high strength and toughness, and an Al–air battery using the POF can output good electrochemical properties. The results demonstrate that the tensile stress of 30 ppi POF is 49.5 kPa owing to the stress-transfer mechanism, while that of PAA is only 3.1 kPa. Compared to that of the PAA hydrogel, the discharging capacity of Al–air batteries with 20 ppi POF can be increased by 79 mAh cm–2 at a current density of 1 mA cm–2, which can be attributed to corrosion inhibition and the surface roughness change of the POF during the discharging process. This work will deliver a selectable strategy for a trade-off between mechanical and electrochemical properties.

Rapid and reversible Na deposition onto Al nanosheet arrays

Fang Tang,Rongqing Xia,Dong Chen,Yu Yao,Lin Liu,Yuezhan Feng,Xianhong Rui,Yan Yu

Sodium metal battery (SMB) is regarded as a promising candidate for next-generation high-energy battery due to high theoretical capacity and abundant natural resources. However, the growth of sodium dendrites and large volume expansion during the processes of sodium plating and stripping seriously restrict the practical application of SMBs. Here, a three-dimensional skeleton of aluminum nanosheet arrays (Al NSARs) is constructed by a facile etching approach to achieve rapid and reversible Na plating/stripping. The Al NSARs with large geometric specific surface and plentiful cavities can provide rich active nucleation sites, reduce local current density and accommodate Na volume change, which lead to uniform deposition of sodium with dendrite-free morphology. As a result, Na plating/stripping on Al NSARs can stably operate over 650 cycles at 2 mA cm −2 /2 mAh cm −2 with average Coulombic efficiency (CE) of 100.0% and low potential polarization of 27 mV. Moreover, the full cell of Na 3 V 2 (PO 4 ) 3 ‖Al NSARs@Na can run for over 1800 cycles at a high rate of 20C. These superior properties, combined with relatively low cost and weight of Al, enable our Al NSARs to be great prospect for practical applications.

Stepwise assembly of multidimensional Al–Pb based coordination polymers

San-Tai Wang,Wei-Hui Fang,Shu-Hua Zhang

The coordination chemistry of the main group elements has always been attractive. Present herein is a stepwise assembly approach toward multidimensional Al–Pb based crystalline compounds. [Al 2 Pb 3 (L) 2 (HL) 2 (μ 3 −OH) 2 ]·2Hdma·2H 2 O·2Cl (AlOC-48) and [AlPb 2 (L) 2 (μ 3 −OH)]·3H 2 O (AlOC-49) (H 3 L ​= ​2,3-dihydroxybenzoic acid, Cat ​= ​catechol and dma ​= ​dimethylamine) represent the first examples of multidimensional Al–Pb based compounds. They are assembled through [Al 4 (L) 4 (Cat) 2 ]] 4- (Al 4 , AlOC-13) polyanions and Pb ions. During the process of coordination assembly, metal site substitution occurs on the Al 4 precursors and transform into Al 2 Pb 2 unit. AlOC-48 and AlOC-49 are two-dimensional and three-dimensional frameworks based on Al 2 Pb 2 clusters. Moreover, the optical band gap and photocurrent response of these two compounds are studied.

Microstructured Al/Fe2O3/Nitrocellulose Energetic Fibers Realized by Electrospinning

Rui Li,Hongmei Xu,Hailong Hu,Guangcheng Yang,Jun Wang,Jinpeng Shen

Laser emission from flash ignition of Zr/Al nanoparticles

Fan Yang,Xiaoli Kang,Jiangshan Luo,Laixi Sun,Handing Xia,Zao Yi,Yongjian Tang

We report the first laser emission from flash ignition of Zr/Al nanoparticles with the addition of strong oxidizer KClO4 using Nd: YAG as a laser medium. The mixture Zr/Al/Kp-45 (mass ratio = 33%Zr: 33%Al: 34%KClO4) has the highest brightness temperature Tb = 4615 K and the adiabatic flame temperature Tf = 4194 K with the duration of 20 ms. At 1064 nm we measured a maximum output energy of 702.5 mJ with the duration of nearly 10 ms by using only 100 mg mixture with an output coupler (transmission T = 10%). Further optimizing the concentration cavity and increasing the mixture content will yield much higher efficiency and output energy.