Heteroatom doping engineering is desirable in tuning crystal structures and electrical properties, which is considered an opportunity to further develop microwave absorption materials. However, the competition mechanism and priority among doped atoms have not been revealed, which are insufficient to guide the most reasonable dielectric coupling model and design highperformance absorbers. In this work, based on in situ N and O, ex situ S is introduced through external thermal driving, leading to fierce competition among anions. Specifically, S atoms replace pyrrole N, drive out lattice O, and create O vacancies, bringing more extensive local charge redistribution and stronger electron interaction, thus activating the defect-induced polarization (3-6 times higher than conduction loss) in the middle/high-frequency region. Therefore, the effective absorption bandwidth (EAB) of 9.03 GHz and the minimum reflection loss (RL min ) of −64.05 dB at a filling rate of 10 wt.% are obtained, which improves the record of carbon absorbers as reported. Through macro-designs, i.e., multi-layer gradient metamaterial, or utilizing other advantages, e.g., cost-effective, stable chemical properties and wideangle absorption, porous carbon may possess a great application prospect in the naval field.

electromagnetic energy conversion workstations" presents a viable approach to address the above challenge, which requires the development of high-performance microwave absorbing (MA) materials. [1][2][3] Metal-organic frames (MOFs), constructed from potential metal units (e.g., Fe, [4] Co, [5] and Ni [6] ) and organic ligand, are possible idea candidates due to the dazzling collocation, easy-to-lock dielectric/magnetic combination, [7,8] as well as favorable electromagnetic coordination and attenuation. [9][10][11] At present, increasingly stringent performance indicators, such as wide electromagnetic absorption bandwidth (EAB >7 GHz), limit the promotion of MOFs. Fortunately, the micro-engineering of such MOFs with cavities, such as yolk-shell, [12][13][14] macroporous, [15,16] and especially hollow, [17,18] has been demonstrated to reduce the density, suppress eddy current, and improve impedance matching. [19] However, traditional hollow routes, such as the external template methods (e.g., SiO 2 , polystyrene, etc.), [20] have been revealed to be time-consuming, complex, and acid-base corrosion. [21,22] Zeolite imidazole frame-67 (ZIF-67) has been the most studied template, in which Co 2+ ions are connected to imidazole Hollow metal-organic frameworks (MOFs) with careful phase engineering have been considered to be suitable candidates for high-performance microwave absorbents. However, there has been a lack of direct methods tailored to MOFs in this area. Here, a facile and safe Ni 2+ -exchange strategy is proposed to synthesize graphite/CoNi alloy hollow porous composites from Ni 2+ concentration-dependent etching of Zeolite imidazole frame-67 (ZIF-67) MOF and subsequent thermal field regulation. Such a special combination of hollow structure and carefully selected hybrid phase are with optimized impedance matching and electromagnetic attenuation. Especially, the suitable carrier transport model and the rich polarization site enhance the dielectric loss, while more significant hysteresis loss and more natural resonance increase the magnetic loss. As a result, excellent microwave absorbing (MA) performances of both broadband absorption (7.63 GHz) and high-efficiency loss (-63.79 dB) are obtained. Moreover, the applicability and practicability of the strategy are demonstrated. This work illustrates the unique advantages of ion-exchange strategy in structure design, component optimization, and electromagnetic regulation, providing a new reference for the 5G cause and MA field.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smtd.202200429.

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Biosensors are essential components for effective healthcare management. Since biological processes occur on molecular scales, nanomaterials and nanosensors intrinsically provide the most appropriate landscapes for developing biosensors. Low-dimensional materials have...