JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Yan Cheng,Yongzhen Ma,Kai Zhou,Zhixin Cai,Yanlong Ma,Binglong Zheng,Huanqin Zhao,Hongwei Zhou,Haibo Yang,Renchao Che
Carbon materials have made significant progress in the field of microwave absorption (MA), but achieving wide effective absorption bandwidth (EAB) at low filler content still remains a great challenge. In this work, we design multi-shell bowl-like mesoporous carbon microspheres (MBMCs) by a facile hard template method for efficient MA. It is demonstrated that the spacing between inner and outer shell and second shell thickness play a vital role on the configuration of carbon microspheres. By controlling the second addition of silica template, the microstructure of carbon microsphere evolves from spherical to bowl shape geometry. Expanded shell spacing is beneficial for forming bowl-like microsphere. The dielectric loss and MA properties are highly associated with the configuration of MBMCs. Well-proportioned MBMCs with appropriate shell spacing present wide EAB of 7.3 GHz under a low filling ratio of 12 wt.%. This work paves a new way to broaden EAB and lower filling content of carbon materials via asymmetric multilayer microstructure design.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Yixuan Xia,Zhigang Xiao,Yinhui Yi,Tingting Liu,Conglin Zhang,Gangbing Zhu
Hollow carbon nanosphere (HCS) has received considerable attentions in electroanalysis owing to its unique advantages in surface area, conductivity, stability and cost, while what is ignored is that the close structure with full sphere of HCS generally causes a great loss in its utility ratio of internal surface and its loading density. In this work, a novel hollow bowl-like carbon nanomaterial (HBCs) with open macropore network, nitrogen-doped HBCs (NHBCs), was designed and used as a highly effective sensing material in electroanalysis for the first time. Selecting carbendazim (CBZ), acetaminophen (ACAP) and dopamine (DA) as three representative analytes respectively from pesticides, environmental pollutants and biomolecules, the analytical performances of NHBCs modified electrode towards these analytes were evaluated. The results demonstrated that NHBCs can exhibit much better analytical performances than nitrogen doped HCS (NHCS). After optimizing various analytical conditions, NHBCs modified electrode possesses considerably low analytical limits and wide linearities towards three analytes: 2.7 nM and 0.005 to 8.0 μM for CBZ, 4.9 nM and 0.01 to 35.0 μM for ACAP, 7.6 nM and 0.05 to 125.0 μM for DA, revealing that the as-proposed HBCs-based material has great potential applications in electrochemical sensing.
研究领域:
材料科学
·
分析化学
·
环境科学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yongxin Qian,Yubo Luo,You Li,Tianshun Xiong,Luyao Wang,Wenguang Zhang,Shuangfu Gang,Xin Li,Qinghui Jiang,Junyou Yang
The limited functionalization of current electronic packaging materials has restricted their use in advanced smart electronic devices with high energy density and low signal delay. In this study, we propose a novel strategy for developing an electronic packaging material (BCN@LDH/EP) that possesses exceptional electromagnetic wave (EMW) absorption, thermal management, and flame-retardant capabilities. BCN@LDH/EP is the double-level hollow core–shell structure (BCN@LDH) composed of a bowl-shaped carbon nanoshell (BCN) and a layered double hydroxide (NiAl-LDH). This structure offers rich heterogeneous interfaces and high specific surface area, thereby generating abundant polarization sites and favorable impedance matching. Consequently, the epoxy resin (EP) shows outstanding EMW absorption performance, with a maximum effective absorption band (EAB) of 6.43 GHz and a minimum reflection loss (RL) value of −55.75 dB at a filling amount of only 10 wt%. Moreover, the closely packed thermally conductive filler BCN@LDH provides a broad pathway for heat transfer within the EP, resulting in a significant thermal conductivity improvement efficiency (η) of ∼170%. Notably, the high-temperature cooling and barrier effects of BCN@LDH also confer excellent flame retardancy to the EP composite, reducing the total heat release (THR) rate by up to 44.9%.
研究领域:
材料科学
·
电气工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Mingjia Lu,Lecheng Liang,Binbin Feng,Yiwen Chang,Zhihong Huang,Huiyu Song,Li Du,Shijun Liao,Zhiming Cui
The electronic conductivity and durability of porous carbon supports can be improved by increasing the degree of graphitization in the material; however, the preparation of highly graphitic porous carbon using conventional furnaces remains a significant challenge. Herein, we demonstrate a universal and highly efficient carbothermal shock strategy that significantly improves the degree of graphitization of porous carbon supports, including bowl-like carbon, hollow carbon spheres, ZIF8-derived carbon, BP2000, and Ketjen EC 300J. Taking bowl-like carbon as an example, we illustrate the synthesis of a graphitized bowl-like carbon (G-BC-S) support and evaluate the performance of PtCo/G-BC-S in the oxygen reduction reaction (ORR) in rotating disk electrodes (RDE) and H 2 /air PEM single cells. PtCo/G-BC-S exhibits faster ORR kinetics than PtCo/BC and Pt/C, with little loss of activity (25%) and only 13 mV of E 1/2 decay after 20000 cycles accelerated stress testing under 1.0–1.5 V vs . a reversible hydrogen electrode (RHE). The significantly enhanced performance of the PtCo/G-BC-S catalyst arises from the high activity and chemical/structural stability of the PtCo intermetallic nanoparticles and from the high degree of graphitization and well-defined porous structure of the bowl-like carbon support, which confers excellent electrical conductivity and oxygen transport properties. This study provides a reliable and universal strategy for the development of high-performance porous carbon supports for practical applications in fuel cells.
研究领域:
材料科学
·
电化学
·
能源材料
·
催化
✓ 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）