生物质衍生磁性碳基复合材料的制备及其吸波性能

为响应国家碳中和、碳达峰目标,解决磁性碳基复合材料制备方法繁杂、能耗高、环境不友好等问题,提出生物质衍生法制备碳基吸波材料的新策略.通过选取香菇为原料,铁盐为金属源,经吸附得到铁/香菇前驱体,后经高温煅烧得到Fe/Fe4 N/C复合材料,对材料的相结构、微观形貌、热稳定性、磁特性等理化性质进行表征,分析其吸波性能.研究...

Biomass-derived magnetic carbon composites towards microwave absorption

In response to the national carbon neutrality and carbon emission peak target and in order to solve the potential preparation problem of magnetic carbon composite,it proposed a new biomass-derived strategy for the preparation of carbon-based microwave absorption composites.The iron/mushroom precursor was obtained by absorbing iron ions,where mushrooms acted as the raw material and iron salt severed as metal source.The Fe/Fe₄N/C composites were acquired by controlled high-temperature pyrolysis,and the phase structure,morphology,thermal stability,magnetic stability,physiochemical properties and microwave absorption performance of composites were analyzed and discussed.It was proved that the increased pyrolysis temperature would improve the crystallinity of magnetic nanoparticles,and that the increases in Fe₄N content would induce the decrease of coercivity and saturation magnetization simultaneously.The high pyrolysis temperature was conductive to the transformation from amorphous carbon to microcrystalline graphite,inducing the increased degree of graphitization degree of carbon components.The Fe/Fe₄N/C composite pyrolyzed at 700℃was regarded as the best microwave absorber.With a composite thickness being 4 mm,the effective bandwidth of microwave that could be absorbed reached to 6.64 GHz,from 4.00 to 10.64 GHz.The appropriate impedance matching and synergistic enhancement of dielectric loss and magnetic loss were considered to be responsible for the intensified microwave absorption.It is believed that the research provides a reference for the preparation of magnetic carbon microwave absorbers,and promotes the popularization and application of biomass-derived method.