Fast assembly of Ag3PO4 nanoparticles within three-dimensional graphene aerogels for efficient photocatalytic oxygen evolution from water splitting under visible light.

Three-dimensional (3D) graphene-based composites have drawn increasing attention in energy applications due to their unique structures and properties. However, the assembly of semiconductor nanoparticles (NPs) in 3D graphene structure is usually a complicated and time-consuming process. Here, we demonstrate a strategy of fast assembling Ag 3 PO 4 NPs within 3D graphene aerogels (GAs) with a facile in situ ion filtration-precipitation method, in which the sequential filtration of Ag + and PO 4 3− solutions through the porous 3D graphene structure enables the fast assembly of well-dispersed Ag 3 PO 4 NPs throughout the 3D GAs. The 3D GAs not only prevent the agglomeration of Ag 3 PO 4 NPs due to the porous and interconnected microstructure but also promote the separation of photo-generated charges in Ag 3 PO 4 due to the excellent electrical conductivity of reduced graphene oxide (rGO) that composes 3D GAs. As a result, the 3D Ag 3 PO 4 /GAs composite shows a considerable enhancement in both the activity and stability in photocatalytic oxygen evolution from water splitting when compared with pristine Ag 3 PO 4 . In addition to Ag 3 PO 4 NPs, the in situ ion filtration-precipitation method is also feasible for fast assembling other semiconductor NPs in 3D graphene structures [ABSTRACT FROM AUTHOR]