Ultra-low reflection electromagnetic interference shielding nanofiber film with effective solar harvesting and self-cleaning

It is urgent to develop low-reflection electromagnetic interference shielding material to shield electromagnetic waves (EMW) and reduce their secondary radiation pollution. Herein, an electromagnetic interference shielding nanofiber film is composed of ZnO and carbon nanofiber (CNF) via electrospinning and carbonization approachs, and subsequently coating perfuorooctyltriethoxysilane as a protective layer. On the one hand, ZnO coated by porous carbon, which is derived from ZIF-8, endows the nanofiber film low reflection property through optimizing impedance matching between free space and the nanofiber film. On the other hand, the nanofiber film possesses high electromagnetic interference shielding efficiency, which is beneficial by excellent electrical conductivity of CNF derived from waste leather scraps. Furthermore, the nanofiber film involves abundant interface, which contributes to high interfacial polarization loss. Thus, the nanofiber film with a thickness of 250 μm has electrical conductivity of 53 S/m and shielding efficiency of 50 dB. The reflection coefficient of the nanofiber film is inferior to 0.4 indicates that most of EMW are absorbed inside the materials and the nanofiber film is effective in reducing secondary radiation contamination of electromagnetic waves. Fortunately, the nanofiber film exhibits outstanding solar harvesting performance (106 ℃ at 1 sun density) and good self-cleaning performance, which ensure that the nanofiber film can work in harsh environments. This work supplies a credible reference for fabricating low-reflection electromagnetic shielding nanofiber film to reduce secondary radiation pollution and facilitates the upcycling of waste leather scraps.

Graphic abstract