本研究探讨N型赝三元半导体掺多壁碳纳米管(MWCNTs)的块体热电材料的热电性能。通过将MWCNTs引入N型半导体基体中,研究了其对热电性能(包括电导率、热导率和Seebeck系数)的影响。结果表明,掺入MWCNTs后,材料的Seebeck系数略有下降,电导...本研究探讨N型赝三元半导体掺多壁碳纳米管(MWCNTs)的块体热电材料的热电性能。通过将MWCNTs引入N型半导体基体中,研究了其对热电性能(包括电导率、热导率和Seebeck系数)的影响。结果表明,掺入MWCNTs后,材料的Seebeck系数略有下降,电导率显著提升,主要是由于MWCNTs的掺入通过提升载流子浓度和引入晶界缺陷,改善载流子传输能力并抑制了声子散射,从而优化材料的热电优值。In this paper, an investigation into the thermoelectric characteristics of N-type pseudo-ternary semiconductor bulk materials, which have been doped with multi-walled carbon nanotubes (MWCNTs), is conducted. The integration of MWCNTs into the N-type semiconductor matrix has been meticulously examined to ascertain its impact on various thermoelectric properties, such as electrical conductivity, thermal conductivity, and the Seebeck coefficient. Findings indicate that the doping process marginally diminishes the Seebeck coefficient of the material, whereas there is a marked enhancement in electrical conductivity. This enhancement is primarily attributed to the augmented carrier transport capabilities, which are a consequence of the increased carrier concentration and the introduction of grain boundary defects, as well as the mitigation of phonon scattering. Consequently, these modifications lead to an optimization of the thermoelectric figure of merit for the material.展开更多
High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow ...High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy.展开更多
The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteri...The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.展开更多
文摘本研究探讨N型赝三元半导体掺多壁碳纳米管(MWCNTs)的块体热电材料的热电性能。通过将MWCNTs引入N型半导体基体中,研究了其对热电性能(包括电导率、热导率和Seebeck系数)的影响。结果表明,掺入MWCNTs后,材料的Seebeck系数略有下降,电导率显著提升,主要是由于MWCNTs的掺入通过提升载流子浓度和引入晶界缺陷,改善载流子传输能力并抑制了声子散射,从而优化材料的热电优值。In this paper, an investigation into the thermoelectric characteristics of N-type pseudo-ternary semiconductor bulk materials, which have been doped with multi-walled carbon nanotubes (MWCNTs), is conducted. The integration of MWCNTs into the N-type semiconductor matrix has been meticulously examined to ascertain its impact on various thermoelectric properties, such as electrical conductivity, thermal conductivity, and the Seebeck coefficient. Findings indicate that the doping process marginally diminishes the Seebeck coefficient of the material, whereas there is a marked enhancement in electrical conductivity. This enhancement is primarily attributed to the augmented carrier transport capabilities, which are a consequence of the increased carrier concentration and the introduction of grain boundary defects, as well as the mitigation of phonon scattering. Consequently, these modifications lead to an optimization of the thermoelectric figure of merit for the material.
基金This work was financially supported by the National Natural Science Foundation of China(52130510,62071120,52075097,52205454,52375413)the Natural Science Foundation of Jiangsu Province(BE2022066,BZ2023043,BK20202006,BK20211562)Science and Technology Program of Suzhou,Jiangsu Province,China(SYG202302).
文摘High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy.
基金supported by the Xi’an Science and Technology Plan Project(Nos.GXYD14.27 and GX2338)the Key Scientific Research Program of Shaanxi Provincial Depart-ment of Education(Nos.22JY046 and 21JY032)+1 种基金the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Tech-nology of North University of China(No.XJZZ202104)the General Project of Natural Science Basic Research Program of Shaanxi Provincial Department of Science and Technology(No.2023-JC-YB-424)。
文摘The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.
