Scholarlink

<p>The relentless advancement of modern communication systems and high-power electronic devices has intensified the challenges of electromagnetic pollution and radar stealth, creating a pressing demand for microwave-absorbing materials that integrate strong absorption, broad bandwidth, and minimal thickness without compromising lightweight characteristics. In this work, we propose an innovative bio-templated approach to fabricate hollow urchin-like MnO<sub>2</sub>/carbon heterostructures (CCS@MnO<sub>2</sub>) using chitosan-derived carbon spheres (CCS) as sacrificial templates. A precisely controlled hydrothermal-calcination process allows for the formation of a unique structure with integrated hollow cavities and radially aligned, dense manganese dioxide (MnO<sub>2</sub>) nanoneedles. This distinct structural design simultaneously reduces material density, extends the propagation path of incident waves through multi-level scattering, and creates a large number of heterogeneous interfaces. The optimized CCS@MnO<sub>2</sub>-400 composite exhibits outstanding microwave absorption performance, achieving a minimum reflection loss (RLₘᵢₙ) of –57.04 dB at an ultrathin thickness of 2.0 mm and an effective absorption bandwidth (EAB, RL ≤ –10 dB) of 4.88 GHz, which surpasses the majority of previously reported MnO<sub>2</sub>- and carbon-based absorbers. Detailed analysis indicates that nitrogen doping, abundant MnO<sub>2</sub>/carbon interfaces, and the fractal hollow morphology work synergistically to improve impedance matching and enhance interfacial polarization, dipole relaxation, and conduction loss. This integrated design effectively breaks the conventional trade-off between thickness and absorption bandwidth. Furthermore, radar cross-section (RCS) simulations confirm excellent stealth performance, with a maximum RCS reduction of 26.65 dB·m<sup>2</sup> at normal incidence. This study establishes a novel structure–function paradigm that combines bio-inspired templating with tailored dielectric interface engineering, offering a scalable and effective strategy for developing advanced lightweight, broadband, and high-performance microwave absorbers for stealth and electromagnetic protection applications.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Bio-templated hollow urchin-like CCS@MnO2 composites with tunable dielectric interfaces for broadband microwave absorption and stealth

  • 期刊论文

  • 发表日期：

    2026年4月7日

查看全文
  • Shi Jin,
  • Xueping Wu

摘要

The relentless advancement of modern communication systems and high-power electronic devices has intensified the challenges of electromagnetic pollution and radar stealth, creating a pressing demand for microwave-absorbing materials that integrate strong absorption, broad bandwidth, and minimal thickness without compromising lightweight characteristics. In this work, we propose an innovative bio-templated approach to fabricate hollow urchin-like MnO2/carbon heterostructures (CCS@MnO2) using chitosan-derived carbon spheres (CCS) as sacrificial templates. A precisely controlled hydrothermal-calcination process allows for the formation of a unique structure with integrated hollow cavities and radially aligned, dense manganese dioxide (MnO2) nanoneedles. This distinct structural design simultaneously reduces material density, extends the propagation path of incident waves through multi-level scattering, and creates a large number of heterogeneous interfaces. The optimized CCS@MnO2-400 composite exhibits outstanding microwave absorption performance, achieving a minimum reflection loss (RLₘᵢₙ) of –57.04 dB at an ultrathin thickness of 2.0 mm and an effective absorption bandwidth (EAB, RL ≤ –10 dB) of 4.88 GHz, which surpasses the majority of previously reported MnO2- and carbon-based absorbers. Detailed analysis indicates that nitrogen doping, abundant MnO2/carbon interfaces, and the fractal hollow morphology work synergistically to improve impedance matching and enhance interfacial polarization, dipole relaxation, and conduction loss. This integrated design effectively breaks the conventional trade-off between thickness and absorption bandwidth. Furthermore, radar cross-section (RCS) simulations confirm excellent stealth performance, with a maximum RCS reduction of 26.65 dB·m2 at normal incidence. This study establishes a novel structure–function paradigm that combines bio-inspired templating with tailored dielectric interface engineering, offering a scalable and effective strategy for developing advanced lightweight, broadband, and high-performance microwave absorbers for stealth and electromagnetic protection applications.