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

Abstract

Layered double hydroxide (LDH) materials have attracted much attention in electromagnetic (EM) wave absorption applications due to their flaky texture and adjustable bimetallic composition. However, the construction of 2D LDH materials, especially metal−organic framework (MOF)-derived LDHs, is usually demanded with high-energy and multi-step processes. Here, the 2D bimetallic Co, Ni-LM nanosheets have been readily prepared by a one-step room-temperature reaction using 2methylimidazole as an inducer molecule and the interlayer equilibrium substance. The precise molar ratio of Co 2+ and Ni 2+ in water/methanol is the controlling factor for the formation of MOF-derived LDH nanosheets. In addition, the well-tuned molar ratio can be extended to the preparation of 2D bimetallic Zn, Ni-LM nanosheets by only changing the Co 2+ ions to Zn 2+ ions, using the same feeding ratio. Then, we apply a temperature-controlled pyrolysis strategy under air to convert Co, Ni-LM and Zn, Ni-LM into their derivatives of Co, Ni-LMc and Zn, Ni-LMc, respectively. Based on the synergistic effects of multi-components and 2D structure, the Co, Ni-LMc material achieves remarkable electromagnetic absorption (EMA) performance, where its maximum width reaches 4.76 GHz with a thickness of 1.9 mm. For Zn, Ni-LMc material, a resonant absorption peak appears around 14.04 GHz for different absorber thicknesses. This work enlightens a facile, green, and environmentally friendly strategy for constructing MOF-derived LDH nanosheets. The unique EM response behavior of the two derivatives also provides us with a positive guidance for the subsequent design of EMA composites to meet the requirements of different application environments.

Metal Organic Frameworks Derived Layered Double Hydroxide Nanosheets for Electrochemical Energy Storage and Conversion

“…[5] This provides the potential for the conversion of MOFs into other materials. [2c,13] Similar strategies applied in the synthesis of MOFs can be also applied in the conversion from MOFs into LDHs, including electrodeposition, [14] straightforward room-temperature stirring, [15] in-situ hydrolysis [16] and etching. [17] For example, Tang et al applied hydrothermal and etching strategies to prepared MOF-derived LDH cages.…”