Optimization of electromagnetic wave absorption properties of CoNi/MoSe2 composites with 3D flower-like by controlling the Co/Ni molar ratio

Abstract

Developing composite materials with a rational composition structure has been a critical strategy to obtain superior electromagnetic (EM) wave absorption materials. CoNi/MoSe2 composites were synthesized by a two-step method in this work. Firstly, the flower-like MoSe2 was synthesized by hydrothermal method, and then the CoNi alloy was loaded on the MoSe2 surface by an electroless plating method. It is worth noting that in this paper, PdCl2 was not used for activation during the electroless plating process, and the flower-like structure of MoSe2 was not destroyed. In order to investigate the effect of different Co/Ni molar ratios on the absorption performance of the CoNi/MoSe2 composites, three samples with Co to Ni molar ratios of 1:3, 1:1, 3:1 and two other samples with only one metal (Ni or Co) were prepared. The analysis results show that the minimum reflection loss(RL) value of Ni/MoSe2 is −18.01 dB and the maximum effective absorption bandwidth(EAB) of Co/MoSe2 is 2.16 GHz. In comparison, the CoNi/MoSe2 composite exhibits the best EM wave absorption performance when the Co/Ni ratio is 1:3, and the minimum RL can reach −48.6 dB at a matching thickness of only 1.8 mm. And when the matching thickness is 1.4 mm, the broadest EAB is 3.76 GHz. Therefore, this work provides a new research idea for the design of broadband and efficient EM wave absorbers.