CoFeCu-ZIF衍生材料的制备及吸波性能研究

Preparation and Microwave Absorption Properties of CoFeCu-ZIF Derived Materials

摘要:

随着科技的迅速发展，电子产品的广泛应用引发了电磁干扰问题，从而影响了人类健康及精密仪器的正常运行，尤其是对国防军工领域的对信息安全构成了严重威胁。金属有机框架（MOF）衍生碳基复合材料因制备简单、力学性能稳定、质量轻、金属配位点丰富等特点，成为备受关注的多损耗机制吸波材料。然而， MOF衍生物的吸波性能目前仍有较大的提升空间。针对这一问题，采用简单的沉淀析出法和煅烧工艺，制备了不同结构的CoFe-ZIF、CoCu-ZIF和CoFeCu-ZIF衍生材料。通过X射线衍射（XRD）和扫描电子显微镜（SEM）对制备材料的物相、形貌及结构进行了表征。结果表明，MOF衍生材料具有六面体或八面体结构，并且其内部存在大量不规则孔洞，这有利于电磁波的衰减。通过调控Fe及Cu金属离子的配位方式，可显著改善衍生材料的吸波性能。吸波性能测试结果表明：CoCu-ZIF样品的最大吸收带宽（EAB）达到了6.3 GHz（厚度1.2 mm），最小反射损耗（RL_min值）达到了-20.98 dB（厚度1.5 mm），展现出优异的吸波性能；CoFeCu-ZIF样品的EAB_max达到了3.36 GHz（厚度2.4 mm），RL_min值为-19.18 dB（厚度4.2 mm），并且在阻抗匹配性能方面表现最佳。通过探索Fe和Cu离子对材料物相及形貌的影响，揭示了MOF衍生材料的吸波性能的变化规律，为MOF体系的系统优化及吸波性能提升提供了新的研究方向。（专精特新·电磁波吸收与屏蔽用新型材料的研究进展专辑十二之七）

Abstract:

With the rapid advancement of science and technology， electronic devices have become widely used， leading to increased electromagnetic interference （EMI）， which can negatively impact both human health and the operation of precision instruments. In particular， EMI poses a significant threat to national defense information security in the military sector. Metal-organic framework （MOF）-derived carbon-based complexes， as popular wave-absorbing materials with multiple loss mechanisms， offer several advantages such as simple synthesis， stable mechanical properties， light weight， and an abundance of metal coordination sites. However， the wave-absorbing properties of MOFs derivatives in existing studies still leaves room for improvement. To address this， CoFe-ZIF， CoCu-ZIF and CoFeCu-ZIF derivatives with different structures were synthesized using a straightforward precipitation method followed by calcination， in which Co²⁺ ions were coordinated with dimethylimidazole and subsequently calcined in an inert atmosphere. X-ray diffraction （XRD） and scanning electron microscopy （SEM） were used to characterize the physical phase， morphology and structure of the prepared materials. Results showed that the derivatives had hexahedral or octahedral faces and contained a large number of irregular pores that promoted the attenuation of electromagnetic waves. By adjusting the coordination modes of Fe and Cu metal ions， significant improvements in wave-absorbing properties were achieved. Performance tests revealed that the CoCu-ZIF sample demonstrated a maximum absorption bandwidth （EAB） of 6.3 GHz （at a thickness of 1.2 mm） and a minimum reflection loss （RL_min） of -20.98 dB （at 1.5 mm）， showcasing excellent wave-absorbing potential. The CoFeCu-ZIF sample achieved an EAB_max of 3.36 GHz （at 2.4 mm） and an RL_min of -19.18 dB （at 4.2 mm）， with superior impedance matching performance. This study explores the influence of Fe and Cu ions on the material’s phase and morphology， and reveals the relationship between these factors and the wave-absorbing performance of MOF derived materials. The findings provide valuable insights for optimizing the MOF system and enhancing its wave-absorbing properties.