【摘 要】
：
In this paper, W-containing SiC-based ceramic nanocomposites were successfully prepared by a polymer-derived ceramic approach using allylhydridopolycarbosilane (AHPCS) as a SiC source, WCl6 as a tungsten source, polystyrene (PS) as a pore forming agent as
【机 构】
：
College of Materials,Key Laboratory of High Performance Ceramic Fibers(Xiamen University),Ministry o
论文部分内容阅读
In this paper, W-containing SiC-based ceramic nanocomposites were successfully prepared by a polymer-derived ceramic approach using allylhydridopolycarbosilane (AHPCS) as a SiC source, WCl6 as a tungsten source, polystyrene (PS) as a pore forming agent as well as divinyl benzene (DVB) as a carbon rich source. High-temperature phase behavior of the W-containing SiC-based ceramics after heat treatment was studied, showing that excessive DVB content in the feed will inhibit the crystallinity of W-containing nanoparticles in the final ceramic nanocomposites. The high specific surface area (SSA) of 169.4–276.9 m2/g can be maintained even at high temperature in the range of 1400–1500℃, due to the carbothermal reaction which usually occurs between 1300 and 1400℃. All prepared W-containing SiC-based nanocomposites reveal electrocatalytic activity for the hydrogen evolution reaction (HER). In detail, compared with reversible hydrogen electrode (RHE), the ceramic sample PWA-2-1300 after heat treatment at 1300℃ has the smallest overpotential of 286 mV when the current density is 10 mA·cm–2 in acid medium, indicating the promising perspective in the water splitting field.
其他文献
The microstructure of polymer-derived ceramics (PDCs) was closely related to processing. This study demonstrated that SiCN matrix prepared by polymer infiltration and pyrolysis (PIP) at 900℃ inside a Si3N4 whisker (Si3N4w) preform with submicro-sized pore
Electromagnetic interference (EMI) shielding materials have received considerable attention in recent years. The EMI shielding effectiveness (SE) of materials depends on not only their composition but also their microstructures. Among various microstructu
MAX phases (Ti3SiC2, Ti3AlC2, V2AlC, Ti4AlN3, etc.) are layered ternary carbides/nitrides, which are generally processed and researched as structure ceramics. Selectively removing A layer from MAX phases, MXenes (Ti3C2, V2C, Mo2C, etc.) with two-dimension
Electric field (E-field) control of magnetism based on magnetoelectric coupling is one of the promising approaches for manipulating the magnetization with low power consumption. The evolution of magnetic domains underin-situ E-fields is significant for th
The giant dielectric behavior of CaCu3Ti4O12 (CCTO) has been widely investigated owing to its potential applications in electronics; however, the loss tangent (tanδ) of this material is too large for many applications. A partial substitution of CCTO ceram
It is possible to improve the machinability of aluminum nitride–hexagonal boron nitride (AlN–h-BN) ceramics while maintaining high strength and high thermal conductivity. The composite ceramics with 0–30 wt％ BN as secondary phase were prepared by hot pres
The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution. To cope with this challenge, exploring high-performance electromagnetic (EM) wave absorbing materials with dielectric and magnetic losses coupling i
The novel dental ceramics can be fabricated at lower temperatures when sol–gel derived lithium disilicate glass ceramics (LDGC) was used as an additive for yttria stabilized tetragonal zirconia polycrystalline (Y–TZP) ceramics. The effect of LDGC on the s
随着信息技术的高速发展和广泛应用,数据作为业务的重要支撑需要精准和可控.电力行业信息系统作为国家关键重要基础设施,在数据方面的安全防护能力,已成为电力业务安全稳健运行的重中之重.分析了电力行业数据方面的防护现状,阐述了电力数据可能面临的风险,提出了针对电力行业数据安全的防护思路.在数据安全技术防护方面,研究了数据生命周期的生存和应用状态;在数据安全管理方面,研究了四个层级的管理需求和管理模式.明确了数据安全保障工作建议,可供行业同仁参考.
AB2O4-type spinels with low relative permittivity (εr) and high quality factor (Q× f) are crucial to high-speed signal propagation systems. In this work, Zn2+/Ge4+ co-doping to substitute Ga3+ in ZnGa2O4 was designed to lower the sintering temperature and