Hydrothermal Synthesis of Reduced Graphene Oxide Using Urea as Reduction Agent: Excellent X-band Electromagnetic Absorption Properties

摘要

We report a strong absorption of microwave energy at X-band(8 GHz to 12 GHz)by N-doped graphene.Attachment of nitrogen on the layered structure of GO improves the reflection loss of GO slab(2.0 mm,thickness)from-10 dB to-25.0 dB with a sharp bandwidth-0.3 GHz.As for the broader bandwidth of about 1.4 GHz,reflection loss is -10.5 dB.This significant absorption may take place by improvement of magnetic property of NG through high magnetic coupling of localized spins induced by a defect on the surface of graphene.N atoms play as the electron trapper,easily influenced by self-magnetic moments and incoming electromagnetic fields to produce electric and/or magnetic losses.Here,urea acts as the reducing agent and N atoms donor for graphene oxide in hydrothermal process at a temperature of 190 °C.