JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Z.H. Tan,L.Z. Ouyang,J.M. Huang,J.W. Liu,H. Wang,H.Y. Shao,M. Zhu
A convenient, high-density and low-cost hydrogen supply technology is essential to hydrogen energy system by providing hydrogen to fuel cell component. Magnesium silicide (Mg 2 Si) can be a good hydrolysis candidate due to its low cost and ability of releasing hydrogen gas during hydrolysis process. However, previous studies have demonstrated that Mg 2 Si could easily produce large amount of silanes during hydrolysis reaction, which may cause serious problem of explosive danger when in contact with air. Here it is the first time that Mg 2 Si was used for generation of hydrogen by a simple and convenient one-step hydrolysis reaction. In this study, hydrolysis kinetics and mechanisms of Mg 2 Si in NH 4 Cl and NH 4 F solutions were investigated. The silanes could be almost completely turned into hydrogen by introduction of fluorine ion during the hydrolysis reaction of Mg 2 Si, leading to very low silanes content in the produced hydrogen. The kinetic studies indicated that when the concentration of the NH 4 F solution increased to 13.0%, the hydrogen generation rate and the reaction yield were improved significantly and reached the best performance, producing 466 mL g −1 H 2 in 10 min and 616 mL g −1 H 2 in 30 min at 25 °C. The activation energy was calculated to be 37.3 ± 0.8 kJ mol −1 . Furthermore, the hydrogen yield and the hydrolysis rate of Mg 2 Si can be further improved by high-energy ball milling. After ball milling for 2 and 5 h, the hydrogen generation yield in 30 min increased to 698 and 771 mL g −1 , respectively, and the activation energy was decreased to 23.9 ± 0.6 kJ mol −1 and 12.9 ± 0.1 kJ mol −1 , respectively. The results revealed that NH 4 F can be a promising reagent for promoting the hydrolysis of Mg 2 Si for onsite hydrogen supply.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Yingying Zeng,Hao Liang,Jieru Pu,Lei Liu,Xiaolong Pan,Hao Luo,Zhenwei Niu,Wei Zhang,Liang Bian
Tungsten disilicide (WSi 2 ) is a promising material for high-temperature applications due to its excellent mechanical properties and superior thermal stability. This study aims to investigate the mechanisms underlying the performance enhancement of polycrystalline WSi 2 and tungsten silicide (W-Si) composites synthesized by high-temperature and high-pressure (HPHT) strategies, focusing on their phase composition and microstructure. The results show that high pressure can effectively reduce the synthesis temperature of the tungsten silicide system, with the phase composition and microstructure of the products being dominated by the treatment temperature. The high intergranular strain resulting from the reactive process and the HPHT environment facilitated the formation of high-density dislocations, including dislocation arrays and networks with multiple orientations, especially near the grain boundaries. Additionally, a 3-nm thick amorphous ribbons were identified between these boundaries. This microstructure, characterized by high-density dislocations and amorphous ribbons, confers exceptional mechanical properties and oxidation resistance. The differences in oxidation behavior between powder and bulk WSi 2 samples underscore the complex relationship between phase stability and material properties under varying processing conditions. These findings indicate that dislocations and amorphous ribbons can achieve in high-temperature ceramics with strong covalent bonding, which is essential for the design and synthesis of advanced W-Si-based ceramics.
研究领域:
材料科学
·
固体力学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Yi Sun,Wenlong Sun,KangKang Zhang,Siyu Cui,Xiong Shao,Jian Qiu,Yushan Yang,Jun Li
In order to improve the specimens’ flame-retardant qualities, ethyl orthosilicate was impregnated into them using a combination of the delignification process and the in situ growing approach. Lignification has been demonstrated to increase the cellular gap of the specimen and to maximize the impregnation of ethyl orthosilicate. Moreover, the in situ growth method results in the combination of specimens containing silica manufactured from ethyl orthosilicate, thereby forming a composite material with enhanced flame-retardant properties. The examination of the changes in the properties of the specimens before and after modification was conducted using FTIR spectroscopy, XRD, XPS, SEM, and other experimental techniques. The modified specimens exhibited higher properties in comparison to the untreated specimens. Furthermore, the modified specimens exhibited enhanced mechanical properties, characterized by an augmented compressive strength of 34.9 MPa and a strength-to-weight ratio of 158 MPa·cm·g–1, in comparison to specimens that did not undergo the modification process. The results of experiments show that proposed green technology provides a new method for producing flame-retardant composites and could significantly improve the mechanical and flame-retardant qualities of wood.
研究领域:
材料科学
·
林业工程
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
SOLID STATE IONICS
·
2023
·
IF 3.2
Jizhe Wu,Chenxin Jin,Guojun Xu,Huaide Chen,Bin Lu,Xiaomin Li,Fugen Sun,Lang Zhou,Zhihao Yue
Silicon monoxide (SiO x , 0 < x < 2) has been one of the new directions of scientific researchers because of some characteristics, such as higher theoretical specific capacity and lower volume expansion efficiency. However, its disadvantages such as the volume expansion effect and poor conductivity still exist in the process of charge and discharge, which limit its commercialization process. In this paper, cuprous oxide and carbon coated silicon monoxide (SiO x /C/Cu 2 O) composites were obtained by high temperature heat treatment. In the SiO x /C/Cu 2 O anodes, carbon can buffer the volume expansion of the lithium intercalation, enhance the conductivity of the material, reduce the contact between the electrolyte and the active substance, Cu 2 O can further reduce the contact between the electrolyte and the active substance, greatly buffer the change of electrode structure and improve the overall cycling performance. After the rate of 0.5C (1C = 2100 mA g −1 ) for 500 cycles, the discharge specific capacity is 704.0 mAh g −1 , about 350 mAh g −1 higher than SiO x , which shows excellent long-cycle ultra-high stability.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yong Qin,Ali Reza Kamali
Layer-structured calcium silicide (CaSi 2 ) is prepared using a fast and clean combustion synthesis (CS) method, employing silica as the silicon source. The CS process was characterized by the occurrence of an ignition reaction at 510 °C, leading to the formation of CaO, CaSi 2 , Ca 14 Si 19 , and Ca 3 SiO 5 which is converted into CaSi 2 with minor amounts of Si after an acid treatment. The mechanism involved in the CS process is discussed. The structure and microstructure of the CS-CaSi 2 is characterized and compared with the commercial CaSi 2 , and the outcomes are discussed based on the Ca-Si binary phase diagram. In comparison with the latter, the CS-CaSi 2 has a considerably greater purity, with loosely stacked structure, providing a surface area of around 43 m 2 g −1 . The thermal analysis of the CS-CaSi 2 is conducted under high purity argon and air flow of 100 mL min −1 , comprising differential scanning calorimetry (DSC) and thermal gravimetric (TG) analysis. The analysis conducted under argon provides evidence for the occurrence of the melting event at 1037 °C. Under air, the material is almost stable below 800 °C, while the oxidation is detected at higher temperatures. The oxidation peak of the material is realized from the corresponding DSC thermogram to take place at 1028 °C. The oxidation event is suggested to occur through two stages. At the first stage (T < 1030 °C), the event can be explained by the oxidation of calcium content of CaSi 2 . The second oxidation stage taking place at higher temperatures can be related to the oxidation of Si, with a lower rate. The Li-storage performances of the commercial CaSi 2 and CS-CaSi 2 are evaluated.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 1
·604-614
·
IF 3.9
Yajie Yu,Shi He,Zhengang Zhang,Haihua Chen,Peipeng Jin,Binnian Zhong,Linhui Zhang,Liping Wang,Cheng Lu
Silicide ceramics are attracted significant attention due to their exceptional physical properties. However, their inherent brittleness at room temperature limits their practical applications. Here, we aim to improve the mechanical properties of tantalum disilicide (TaSi 2 ) ceramics by modifying the preparation methods and sintering conditions. We fabricate the dense TaSi 2 ceramics using high-pressure and high-temperature (HPHT) sintering technology at 5.5 GPa and 800–1300°C. We characterize the microstructures, mechanical, and electronic properties of bulk TaSi 2 ceramics at HPHT conditions. Our results indicate an enhancement in the fracture toughness of 11.97 MPa m 1/2 for TaSi 2 ceramics. More importantly, the electrical conductivity (47.13 × 10 5 S/m) of TaSi 2 ceramic is increased and verified by theoretical calculations. These findings provide crucial insights for future applications of TaSi 2 and offer valuable avenues for the design and synthesis of advanced ceramic materials.
研究领域:
材料科学
·
固体力学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-8
·
IF 12.121
Sun Yong,Sun Bo,He Jingbo,Yang Guowei,Wang Chengxin
Providing high performance electrical nano-interconnects for micro-nano electronics that are robust in harsh environments is highly demanded. Today, electrical nano-interconnects based on metallic nanowires, e.g. Ag and Cu, are limited by their positive physicochemical reactivity and ductility under large strain (i.e. irreversible dislocations and local necking-down elongation) at high temperatures or in strong oxidizing and acidic environments. Herein, to overcome these limitations, high-quality millimetre-sized soft manganese-based silicide (Mn 5 Si 3 @SiO 2 ) nanowire nanocables are designed via a glassy Si–Mn–O matrix assisted growth. The proposed nanocables exhibit good electrical performance (resistivity of 1.28 to 3.84×10 -6 Ωm and maximum current density 1.22 to 3.54×10 7 A cm −2 ) at temperatures higher than 317°C in air atmosphere, strongly acidic (HCl, PH=1.0) and oxidizing (H 2 O 2 , 10%) ambient, and under complex electric field. The proposed Mn 5 Si 3 @SiO 2 nanocables, which withstand a strain of 16.7% free of failure, could be exploited for diverse applications in flexible electronics and complex wiring configurations.
研究领域:
材料科学
·
纳米技术
·
电子工程
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Kaixuan Yang,Xiao Chen,Zongxuan Bai,Changhai Liang
Development of highly efficient and long stable hydrodesulfurization (HDS) catalysts still is a great challenge for the refining industry. In this work, a series of intermetallic noble metal silicides supported by carbon nanotubes catalysts (Pt 2 Si/CNTs, Rh x Si/CNTs, and RuSi/CNTs) have been developed by chemical vapor deposition successfully, using dichlorodimethylsilane as Si source. These materials were used as efficient catalysts for the deep HDS of dibenzothiophenes (4,6-DMDBT and DBT) and performed high selectivity to the direct desulfurization pathway. The sequence of HDS activity over noble metal silicides catalysts is in keeping with the sequence of HDS activity of the corresponding metal catalysts, which is Pt 2 Si/CNTs > Rh x Si/CNTs >> RuSi/CNTs. In addition, the Pt 2 Si/CNTs performed an excellent stability in 100 h stability testing for HDS of 4,6-DMDBT. Therefore, this sulfur-tolerant noble metal silicides could be as promising catalysts for the ultra-deep HDS of fossil-fuel.
研究领域:
催化化学
·
能源化工
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Yuying Jiang,Xibin Zhou,Yifeng E,Pengyan Wei,Peng Chen,Li Li,Zhuozhe Li,Thomas F. Krenzel,Kun Qian
The design and synthesis of novel electrode catalysts is an applicable strategy to improve the performance of direct methanol fuel cells (DMFCs). The catalyst is composed of molybdenum disulfide as the shell and nickel silicide-doped sodalite (MoS 2 /NiSi@SOD) as the core. A series of characterization results indicate that NiSi is highly dispersed in the nanosized SOD cage on the surface of the SOD zeolite at the crystal faces of (011), (102), and (201). A thin conductive protective cover is formed by MoS 2 on the surface of the zeolite . By the cyclic voltammetry (CV), the catalyst performs a maximum current density of 46.9 mA cm −2 (1250.1 A g Ni −1 ) with 10 M methanol while no remarkable catalyst poisoning and catalyst deactivation are observed. It is revealed that MoS 2 /NiSi@SOD under high catalysis activity protects the Ni from the drain in the alkaline electrolyte , leading to a broad application prospect as a noble-metals-free DMFC catalyst.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2024
·
IF 2.4
Liu Ting-Ting,Ye Zhuo-Feng,Li Shang-Qi,Zhang Yi,Zhang Yao-Wen,Li Xin-Tao,Du Fei-Hu
Silicon, with its many advantages, is gaining attention in the field of lithium-ion battery anode materials. However, severe volume swelling, poor conductivity, and slow Li + diffusion kinetics are major obstacles to enhancing the electrochemical properties of silicon anodes. One-dimensional silicon nanowires with a high aspect ratio can effectively ameliorate these issues, while the complexity of the synthesis method limits its development. Here, a three-dimensional flexible electrode of binary-phase Ni-silicide foam loaded with silicon nanowires (Ni x Si y @Si NWs) was constructed in two simple steps: preparation of metal catalyst nanoparticles using a chemical plating approach and production of silicon nanowires by the supercritical fluid-liquid–solid mechanism. Benefiting from the excellent anchoring ability and superior electrical conductivity of Ni x Si y as well as the extra space and favorable Li + and electrolyte diffusion paths provided by the Si NWs network, the as-obtained anode exhibits a high initial Coulombic efficiency of 77% at 0.5 A g −1 , excellent cycling performance (a reversible capacity of 1238 mAh g −1 after 200 cycles) and outstanding rate capability (2675, 2497, 2164, 1740, and 1222 mAh g −1 at 0.5, 1, 2, 4, and 8 A g −1 , respectively).
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Hao Xiong,Anze Shui,Qingliang Shan,Shenghui Zeng,Xiuan Xi,Bin Du
Polishing porcelain stoneware tile residues (PPR) is used to prepare foamed ceramic to solve the problem of solid waste discharge in ceramic industry. In this study, C, Al and Si powder were added to the simulated PPR to control foaming, and the mechanism of silicon carbide foaming in the PPR was discussed in detail. After these powders were introduced into the simulated PPR, the phenomenon of alumina crystallization on the pore wall of the foamed ceramic and the diffusion of gas in the foamed ceramic were discovered to be exciting. The foaming mechanism of PPR is detailed as follows: the diffusion rate of oxygen in silicate liquid is faster than that of CO during sintering, so the CO generated by incomplete oxidation of silicon carbide in PPR accumulates in the liquid, which makes the volume of ceramics expand and causes foaming.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2020
·Vol. 23
·期 1
·2000691
·
IF 3.217
Lu Zhu,Xuanru Ren,Xueqin Kang,Ping Zhang,Peizhong Feng,Xiaohong Wang
MoSi 2 coatings are prepared using spent and commercial MoSi 2 powders as raw materials to protect niobium (Nb) substrate by spark plasma sintering (SPS) technique, and the microstructure and oxidation resistance of the coatings at 1500 °C are investigated. Results showed that obvious pores are found in MoSi 2 coating using commercial MoSi 2 (MC coating) after SPS while MoSi 2 coating using spent MoSi 2 (MS coating) is dense with low porosity. (Mo,Nb) 5 Si 3 diffusion layer is generated between MS coating and the substrate with no gap or cracks, showing excellent metallurgical bonding. After long-term oxidation at elevated temperature, pores and exposed Mo 5 Si 3 can be observed in the oxide scale of MC coating, while dense and complete oxide scale is obtained by MS coating. Lowest mass gain (2.78 mg cm −2 ) is acquired by MS coating after oxidation at 1500 °C for 40 h because SiO 2 oxide scale is completely formed on the dense and bentonite-containing coating, blocking the diffusion of oxygen at high temperature. Compared with MC coating, no further oxidation occurs inside the MS coating or substrate, exhibiting better high-temperature oxidation resistance.
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
危险品化学品经营许可证（带存储）