High microwave absorption performance of NiS2/rGO nanocomposites with a thin thickness

Microwave absorption materials with high reflection loss (RL), thin thickness and wide absorption bandwidth have attached a lot of attention for overcoming microwave pollution. Nanocomposites composed of carbon-based materials and metal sulfide have excellent microwave absorption properties, which meet the high RL of low weight microwave absorbing materials. In this study, binary nanocomposites of spherical-like nickel sulfide (NiS2) decorated on reduced graphene oxide (rGO) were successfully prepared using a one-step single-mode microwave-assisted hydrothermal method. Morphological analysis using scanning electron microscopy and transmission electron microscopy indicated that the NiS2 particles were evenly wrapped by rGO. The rGO/NiS2 nanocomposites were used as microwave absorption materials and their electromagnetic parameters were measured in the range of 1.0–18.0 GHz. For the rGO/NiS2 1:5 nanocomposite with a very thin thickness of 1.59 mm, the minimum RL and effective absorption bandwidth reached −33.72 dB and 4.37 GHz, respectively. The microwave absorption performance of the nanocomposites improved by adjusting the impedance upon changing the mass fraction of NiS2. Therefore, rGO/NiS2 nanocomposites with high RL and thin thickness have great application prospects for microwave absorption.