Superhydrophobic nanocomposites of erbium oxide and reduced graphene oxide for high-performance microwave absorption

Engineering of electromagnetic wave absorbing materials featuring long-term durability in harsh outdoor environments (e.g., humidity, acid, and alkali conditions) is meaningful for their effective and sustainable implementation. Herein, morphology-controlled erbium oxide-reduced graphene oxide composites are designed for effective absorption of electromagnetic microwaves either in an acidic or alkaline environment. The engineered nanocomposites with chrysanthemum-like structures display good impedance matching, moderate attenuation constant, exchange resonance, natural resonance, multiple reflections, and polarization relaxations, therefore exhibiting excellent microwave absorption capacity with a minimum reflection loss of -37.18 dB and an effective absorption bandwidth of 5.1 GHz. In addition, the chrysanthemum-like composite also displays self-cleaning property, strong weatherability, and acid- and alkali-resistance, enabling sustained electromagnetic wave absorbing performance even in corrosive conditions (1 M HCl, 1 M NaOH). The findings indicate that, through structural engineering, erbium oxide-reduced graphene oxide composites can serve as a promising microwave absorber in harsh outdoor environments.