Tunable electromagnetic and enhanced microwave absorption properties in CoFe2O4 decorated Ti3C2 MXene composites

•Magnetic CoFe2O4-decorated Ti3C2 MXene were successfully prepared.•Tunable electromagnetic properties were observed in the CoFe2O4-Ti3C2 MXene.•A broad effective bandwidth of 8.5 GHz was achieved. Ti3C2 MXene has demonstrated to be a potential microwave absorber if some difficulties, e.g., poor impedance matching and lack of magnetic loss, can be well-solved. In this paper, laminated Ti3C2 MXene was synthesized using the HF etching method. CoFe2O4 nanoparticles-decorated Ti3C2 MXene (CoFe2O4-Ti3C2) composites were then fabricated via a novel in-situ solvothermal process. The incorporation of CoFe2O4 nanoparticles on the electromagnetic (EM) and microwave absorption properties of Ti3C2 MXene were systematically studied over 2–18 GHz. Interestingly, increased percolation threshold and controlled complex permittivity were well-observed in the CoFe2O4-Ti3C2 composites. Furthermore, additional magnetic loss due to the existence of magnetic CoFe2O4 was easily obtained. Benefiting from tunable electromagnetic properties, the minimum reflection loss (RL) value of the CoFe2O4-Ti3C2-filled absorbing coating achieved −30.9 dB with a matching thickness of only 1.5 mm. A wide effective absorption bandwidth (RL