3D Fe3O4 nanoparticle/graphene aerogel for NO2 sensing at room temperature

Abstract

Three-dimensional graphene aerogel-supported Fe₃O₄ nanoparticles for efficient detection of NO₂ at room temperature are reported. The graphene composite exhibits an interconnected macroporous framework of graphene sheets with uniform dispersion of Fe₃O₄ nanoparticles. Such a hybrid nanostructure would effectively facilitate target gas diffusion and exhibit significantly higher response and faster recovery speed than pure reduced graphene oxide, highlighting the importance of the 3D macropores and high specific surface area of the graphene aerogel support for improving sensing performance. We also propose a hybrid sensing mechanism for the drastic improvement in the sensing behavior which combines the resistance modulation of Fe₃O₄ nanoparticles/graphene heterointerfaces in addition to the radial modulation of the surface depletion layer of the Fe₃O₄ nanocomposite.