Ultralight and flexible graphene foam coated with Bacillus subtilis as a highly efficient electromagnetic interference shielding film

The rapid advancement of electromagnetic appliances in daily life has caused a serious problem of electromagnetic interference (EMI). The demand of efficient materials for the shielding of electromagnetic waves is increasing day by day. Here, we report the assembly of Bacillus subtilis-modified graphene foam (BS-GF) with ultralight weight, significant flexibility and remarkable EMI shielding effectiveness (SE). BS-GF with a thickness of 1 mm and density of 0.18 g cm(-3) shows a total EMI-SE of 56 dB in the 8-12 GHz band, and the specific EMI-SE reaches as high as 311 dB cm(3) g(-1). After folded 5000 times along the central axis, the sample does not show any significant reduction in EMI-SE. These excellent properties come from the light core-shell structure of the bacterial combined with GF, as well as the electrical loss due to GF architecture and the chiral absorbing ability of biomolecules such as DNA in the Bacillus subtilis (BS). The outcomes light the way to large-scale preparation of environmentally friendly and efficient EMI absorbents utilizing the microorganism as precursors.