Synergistic Densification in Hybrid Organic‐Inorganic MXenes for Optimized Photothermal Conversion

Anion defect engineering is proven to be an efficient approach to reconstruct the electronic configuration of carbon‐based magnetoelectric materials for targeted modulation of electromagnetic (EM) performance. However, traditional mono‐anionic doping suffers from low defect concentration and lacks diverse polarization mechanisms. In this work, multi‐anions (N/S/F) stepwise‐doped carbon/Fe3C magnetoelectric composites are elaborately constructed, wherein the predesigned N defects serve as activated sites for anomalously adopting S anions (Step I) and subsequent F anions (Step II) in non‐marginal areas of the carbon layer. It is found that S prefers to replace pyrrolic N defects while F tends to form dangling bonds with the C site adjacent to the pyridinic N. Intriguingly, besides the inherent polarized resonance of N defect at ≈15 GHz, customized S and F defects induce new polarization resonances at ≈10 GHz and ≈15+ GHz, respectively. Under a typical multi‐polarization effect with the synergetic magnetic response, the carbon/Fe3C composites with N/S/F defects harvest the broadest bandwidth of 8.28 GHz (9.72–18 GHz) at 2.55 mm, covering a wide frequency range almost from X to Ku bands. This work demonstrates the positive impact of localized multi‐defects customization and multi‐polarization effect on expanding microwave absorption bandwidth, providing valuable insights for the advanced design of ultra‐broadband absorbers.

The Elaborate Design of Multi‐Polarization Effect by Non‐Edge Defect Strategy for Ultra‐Broad Microwave Absorption

Fang,

Liu,

et al. 2024

MXene and Polymer Collision: Sparking the Future of High‐Performance Multifunctional Coatings

He,

Cui,

Chen

et al. 2024

The development of nanomaterials is crucial to upgrading of modern industry. MXene nanosheets have attracted significant attention due to their superb resistance to permeation, diverse surface chemical properties, impressive mechanical properties, and metal‐like electrical and thermal conductivity, etc., providing unique advantages in various technical fields. When MXene nanosheets are combined with polymers to form functional coatings, their applications span multiple fields, including anticorrosion, wear resistance, flame‐retardancy, electromagnetic interference (EMI) shielding, and de‐icing. This review, in conjunction with MXene's barrier property, lubricity, thermal stability, conductivity, and photothermal conversion property, discusses in detail the various applications of MXene‐based polymer coatings. Additionally, it examines the dispersion and interaction of MXene within polymer coatings and the role of functionalized MXene in polymers. Finally, based on the current research status and emerging needs, the development challenges and future research opportunities of MXene‐based polymer coatings in a targeted manner are discussed. This review aims to summarize the existing research results and put forward an objective and fair point of view, providing a constructive reference for upgrading modern nanofunctional polymer coatings.

Achieving Broadband Microwave Shielding, Thermal Management, and Smart Window in Energy‐Efficient Buildings

Tan,

Guo,

et al. 2024

Energy‐efficient building materials are eye‐catching for reducing indoor energy consumption via eliminating electromagnetic interference and pollution, controlling the thermal transfer, and promoting sunlight harvesting and providing a comfortable living environment. To realize broadband microwave shielding, the elaborate control of microstructures has showed great potential and research direction. By composition regulation and structure design with various dimension, the synergistic effects including conductive networks, interfacial polarization, magnetic coupling, dipole polarization, and dielectric‐magnetic synergy, can significantly improve electromagnetic (EM) shielding capacity. Thermal management including thermal conversion, thermal storage, thermal radiation, and thermal conduction has enormous potential in enhancing the sustainability and energy efficiency for future buildings. Smart windows are able to switch optical transmittance and colors, which is contributed to saving building energy. Herein, in this review, the recent progress of broadband shielding, thermal management, and smart window in the field of energy‐efficient buildings is summarized, from the aspects of materials, mechanisms, and scenarios. Further, the main bottlenecks and problems are discussed, and potential research opportunities are further highlighted.