Biomimetic 3D Coral Reef-like GO@TiO2 Composite Framework Inlaid with TiO2-C for Low-Frequency Electromagnetic Wave Absorption

Abstract Improving the non-magnetic low-frequency electromagnetic (EM) wave performances of common microwave-absorbing materials is yet very difficult and depends on the assistance of structural design to realize tremendous microwave reflectance absorption in a limited space. Herein, a biomimetic three-dimensional coral reef-like graphene oxide (GO)@TiO2 composite framework was prepared with porous TiO2-C inlaid subunits derived from MIL-125 (Ti), which provided an effective platform for concentrating two unusual structures of TiO2 and carbon sources into single particles. The formation mechanism of the material was analyzed in detail. Compared with GO@TiO2/TiO2-C composite materials at varying mass ratios, the minimum RL of GO@TiO2/TiO2-C-15 is -64.4 dB at 7.4 GHz, and the intensity of -25 dB (>99% energy absorption) can be improved at different thickness, which exhibits an excellent low-frequency EM absorption behavior. Simultaneously, GO@TiO2/TiO2-C-15 has obvious extended performances, including antimicrobial activities and low infrared emissivity, which demonstrate the versatility and application potential of non-magnetic low-frequency microwave absorbers in wearable devices and other fields. The new material is beneficial to reducing the EM waves-caused threat to human health in communication band and to attaining the sustainable utilization of EM waves.