Non‑Magnetic Bimetallic MOF‑Derived Porous Carbon‑Wrapped TiO2/ ZrTiO4 Composites for Efficient Electromagnetic Wave Absorption

Modern communication technologies put forward higher requirements for electromagnetic wave(EMW)absorption materials.Metal-organic framework(MOF)derivatives have been widely concerned with its diverse advantages.To break the mindset of magneticderivative design,and make up the shortage of monometallic non-magnetic derivatives,we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption.The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415(TiZr-MOFs)are qualified with a minimum reflection loss of−67.8 dB(2.16 mm,13.0 GHz),and a maximum effective absorption bandwidth of 5.9 GHz(2.70 mm).Through in-depth discussions,the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed.Therefore,this work confirms the huge potentials of nonmagnetic bimetallic MOFs derivatives in EMW absorption applications.

Metal sulfides based composites as promising efficient microwave absorption materials:A review

The increasingly severe electromagnetic microwave pollution raises higher requirements for the development of efficient microwave absorption(MA)materials.Metal sulfides are regarded as potential robust MA materials because of their unique optical,thermal,electrical,and magnetic properties,as well as the controllable microstructures.However,due to the limited MA performances of unary metal sulfides,morphology regulations and foreign materials hybridizations are adopted as effective strategies to improve their MA performances.Recent years witnessed the fast research progresses on the metal sulfides based MA materials and thus,a systematic literature survey on the materials design,fabrication,characterizations,MA behaviors,and the mechanisms behind is,highly desirable to summarize the rapid progress of this hot research area so as to provide guidance for the future development trend.This review firstly reviewed the research background,research progress,and basic principles of MA materials.Subsequently,the present synthetic methods and performance improvement strategies of metal sulfides based MA materials are systematically introduced.Then,by comparing the MA properties of one-dimensional,two-dimensional,and three-dimensional metal sulfides based composites,the influence of dimensionality and morphology on the MA properties are analyzed.By summarizing the research process of metal sulfides/dielectrics composites,metal sulfides/magnets composites,and metal sulfides/dielectrics/magnets composites MA materials,the influence of foreign materials hybridizations on the loss mechanisms and impedance matching conditions of metal sulfides based composites are revealed.Finally,the challenges and development prospects of metal sulfides based MA materials are presented.This review would provide a comprehensive understanding and insightful guidance for the exploration and development of efficient MA materials with thin thickness,light weight,wide absorption bandwidth,and strong absorption intensity.