Stöber-like method to synthesize ultralight, porous, stretchable Fe2O3/graphene aerogels for excellent performance in photo-Fenton reaction and electrochemical capacitors

Abstract

We report three-dimensional (3D) graphene-based hybrids of Fe₂O₃ nanocrystals grown in situ on graphene aerogels (Fe₂O₃/GAs) by a Stöber-like method. Compared with other reported Fe₂O₃/3D-graphene, Fe₂O₃/GAs have outstanding mechanical strength, high elasticity, ultralow mass, excellent electrical conductivity, good oil absorption capacity and a dispersion of nanoparticles. They have a 3D network structure with a high surface area of 316 m² g⁻¹ and physicochemical stability. 3D-GAs can inhibit the loss of Fe²⁺ and stabilize the conversion of Fe³⁺/Fe²⁺ in the photo-Fenton reaction. Compared with Fe₂O₃ and Fe₂O₃/2D-graphene (Fe₂O₃/GR), Fe₂O₃/GAs exhibit an ultrastable, solar-driven Fenton activity over a wide pH range of 3.5–9.0 for the first time. In addition, the highly-dispersed, nanosized Fe₂O₃ on the surface of the GAs makes the composite highly suitable for use in electrochemical capacitors. Although the Fe₂O₃/GAs only contain 18.3 wt% Fe₂O₃, they still yield a high and stable capacitance (151.2 F g⁻¹) at a high discharge current density of 10 A g⁻¹, which is better than that of Fe₂O₃/GR (93.6 F g⁻¹).