Ambient Synthesis of Metal-Organic Framework-Derived Bimetallic Layered Double Hydroxide Nanosheets by the Composition Inheritance Strategy for Efficient Microwave Attenuation Applications

Layereddouble hydroxide (LDH) materials have attracted much attentionin electromagnetic (EM) wave absorption applications due to theirflaky texture and adjustable bimetallic composition. However, theconstruction of 2D LDH materials, especially metal-organicframework (MOF)-derived LDHs, is usually demanded with high-energyand multi-step processes. Here, the 2D bimetallic Co, Ni-LM nanosheetshave been readily prepared by a one-step room-temperature reactionusing 2-methylimidazole as an inducer molecule and the interlayerequilibrium substance. The precise molar ratio of Co2+ andNi(2+) in water/methanol is the controlling factor for theformation of MOF-derived LDH nanosheets. In addition, the well-tunedmolar ratio can be extended to the preparation of 2D bimetallic Zn,Ni-LM nanosheets by only changing the Co2+ ions to Zn2+ ions, using the same feeding ratio. Then, we apply a temperature-controlledpyrolysis strategy under air to convert Co, Ni-LM and Zn, Ni-LM intotheir derivatives of Co, Ni-LMc and Zn, Ni-LMc, respectively. Basedon the synergistic effects of multi-components and 2D structure, theCo, Ni-LMc material achieves remarkable electromagnetic absorption(EMA) performance, where its maximum width reaches 4.76 GHz with athickness of 1.9 mm. For Zn, Ni-LMc material, a resonant absorptionpeak appears around 14.04 GHz for different absorber thicknesses.This work enlightens a facile, green, and environmentally friendlystrategy for constructing MOF-derived LDH nanosheets. The unique EMresponse behavior of the two derivatives also provides us with a positiveguidance for the subsequent design of EMA composites to meet the requirementsof different application environments.