Fabrication of flower-like Ni0.5Co0.5(OH)2@PANI and its enhanced microwave absorption performances

Abstract Ni 0.5 Co 0.5 (OH) 2 with flower-like structure@PANI was designed and synthesized via a two-step route. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) results illustrated that the Ni 0.5 Co 0.5 (OH) 2 had a 3D flower structure with a homogeneous distribution. The Ni 0.5 Co 0.5 (OH) 2 was coated by polyaniline (PANI) and embedded in polyaniline matrix. The as-synthesized Ni 0.5 Co 0.5 (OH) 2 @PANI possessed a BET specific surface area of 58.82 m 2 g −1 , and its pore diameter was in the mesoporous range (3.93 nm). Investigations of EM wave absorption properties indicated that the maximum absorption intensity of Ni 0.5 Co 0.5 (OH) 2 @PANI was as high as −39.8 dB at 6.4 GHz and the absorption bandwidth exceeding −10 dB was 3.1 GHz (4.9–8 GHz) with a matching thickness of 2.5 mm. The excellent EM wave absorption properties of the material were ascribed to its high permittivity and improved impedance matching effect. Therefore, it is anticipated that the Ni 0.5 Co 0.5 (OH) 2 @PANI composite would serve as a promising microwave absorber.