Bimetallic porphyrin MOF derived CuIn particles/carbon composites as ideal microwave absorbers

Abstract

The purposive and rational construction of novel multicomponent composites is highly attractive in order to achieve outstanding electromagnetic wave absorption properties. Transition metal–carbon composites derived from metal–organic frameworks (MOFs) have received increasing attention in this field. In our work, copper and indium metals were directly embedded in the dual active sites of porphyrins consisting of a central ring (N–H) and a peripheral carboxyl group (COOH) by employing a facile solvothermal process to prepare the single-crystal material of CuIn-PMOFs with periodically arranged structures (C₅₀H₃₂CuInN₅O₈). Afterwards, copper indium/carbon nitrogen (CuIn/CN) composites were synthesized via only in situ pyrolysis of CuIn-PMOFs without further adjustment of the bimetallic ratios. Concretely, due to the improved impedance matching and increased dielectric loss, the CuIn/CN composites prepared at 600 °C (CuIn/CN-600) display a maximum reflection loss (RL) of −78.42 dB at 13.84 GHz with an effective absorption bandwidth (EAB) of about 5.92 GHz (12.08–18 GHz) at 1.92 mm. Therefore, our work delivers a convenient and advanced prototype for the design of controllable MOF-derived composites as exceptional microwave absorbers with high absorption and broad bandwidth.