Microwave-Assisted Synthesis of Boron and Nitrogen co-doped Reduced Graphene Oxide for the Protection of Electromagnetic Radiation in Ku-Band.
The electromagnetic interference (EMI) shielding of reduced graphene oxide (MRG), B-doped MRG (B-MRG), N-doped MRG (N-MRG), and B-N co-doped MRG (B-N-MRG) have been studied in the Ku-band frequency range (12.8-18 GHz). We have developed a green, fast, and cost-effective microwave assisted route for synthesis of doped MRG. B-N-MRG shows high electrical conductivity in comparison to MRG, B-MRG and N-MRG, which results better electromagnetic interference (EMI) shielding ability. The co-doping of B and N significantly enhances the electrical conductivity of MRG from 21.4 to 124.4 Sm(-1) because N introduces electrons and B provides holes in the system and may form a nanojunction inside the material. Their temperature-dependent electrical conductivity follows 2D-variable range hopping (2D-VRH) and Efros-Shklovskii-VRH (ES-VRH) conduction model in a low temperature range (T<50 K). The spatial configuration of MRG after doping of B and N enhances the space charge polarization, natural resonance, dielectric polarization, and trapping of EM waves by internal reflection leading to a high EMI shielding of -42 dB (∼99.99% attenuation) compared to undoped MRG (-28 dB) at a critical thickness of 1.2 mm. Results suggest that the B-N-MRG has great potential as a candidate for a new type of EMI shielding material useful in aircraft, defense industries, communication systems, and stealth technology.
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Sima
S
Umrao
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Tejendra K
TK
Gupta
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Shiv
S
Kumar
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Vijay K
VK
Singh
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Manish K
MK
Sultania
Department of Mechanical Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Jung Hwan
JH
Jung
Department of Mechanical Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Il-Kwon
IK
Oh
Department of Physics, Banaras Hindu Universisty , Varanasi 221005, India.
Anchal
A
Srivastava
EMI shielding; electrical conductivity; microwave; reduced graphene oxide; variable range hopping