Novel Straw-Derived Carbon Materials for Electromagnetic Interference Shielding: A Waste-to-Wealth and Sustainable Initiative

Biomass resources are growing in concern in electromagnetic interference (EMI) shielding due to the advantages of low-cost, sustainability, and unique structural feature. From the perspective of "waste to wealth" and sustainable development, novel straw-derived hollow porous carbon-tube arrays (SCAs) have been fabricated through direct carbonization of wheat straw followed by orderly assembly for the first time. The resultant SCAs with increased SC diameter of ∼1.7–3.3 mm showed not only low apparent density of ∼72–33 mg/cm3 due to the presence of arrayed hollow macrostructure, but also high EMI SE of ∼57.7–44.0 dB coming from both the strong EM reflection and conductive dissipation, as well as hierarchical internal multiple reflections. After the further construction of ultralight graphene aerogel (GA) in their hollow interior, the GA/SCAs with slightly increased density of only ∼78–39 mg/cm3 exhibited obvious SE enhancement of ∼66.1–70.6 dB compared to those of neat SCAs. In addition, the performance comparison between our SCAs and other previously reported carbon foams also revealed the more advanced configuration of hollow porous carbon-tube array for lightweight and high-performance EMI shielding application.