High efficiency and great tunability are becoming hot spot in microwave absorption, drawing great interests of global health researchers. However, meeting the two factors is still a tough challenge. In this work, we demonstrate an easily-tailored absorber of Fe₃O₄ clusters-nitrogen doped graphene by a facile strategy of confined growth. Small magnetic clusters are uniformly implanted on nitrogen doped graphene, which realizes synergy of dielectric and magnetic loss with good conductivity and improved impedance matching. More significantly, tailoring small Fe₃O₄ clusters successfully tunes microwave absorption and bandwidth. The minimum reflection loss is greatly increased by ∼7 times, achieving −53.6 dB, and the effective bandwidth reaches ∼5 GHz with only 1.8 mm thickness. Moreover, tailoring the small clusters also drives the absorption peaks from 4.6 to 14.7 GHz, covering ∼60% of the investigated frequency. This highly efficient and even frequency-selective microwave absorption endows Fe₃O₄ clusters-nitrogen doped graphene with wider applications in electromagnetic shielding, microwave absorption, healthcare, information safety and military fields.

高效和可调谐性正成为微波吸收的热点，引起了全球卫生研究人员的浓厚兴趣。但是，满足这两个因素仍然是一个艰巨的挑战。在这项工作中，我们展示了一种易于控制的Fe ₃ O ₄团簇-氮掺杂石墨烯的吸收剂，该吸收剂采用局限性生长的简便策略。将小的磁簇均匀地注入到掺杂氮的石墨烯上，从而实现介电和磁损耗的协同作用，并具有良好的导电性和改善的阻抗匹配性。更重要的是，定制小的Fe ₃ O ₄簇成功地调节了微波的吸收和带宽。最小反射损耗增加了约7倍，达到了-53.6 dB，有效带宽只有1.8 mm时达到了约5 GHz。此外，定制小簇还可以将吸收峰从4.6 GHz提升到14.7 GHz，覆盖了研究频率的约60％。这种高效且频率选择性的微波吸收技术使Fe ₃ O ₄团簇氮掺杂石墨烯在电磁屏蔽，微波吸收，医疗保健，信息安全和军事领域中具有更广泛的应用。