Three-dimensional Printing of Silver Nanoparticle-Decorated Graphene Microarchitectures

The functionalization of graphene with inorganic nanomaterials has attracted widespread attention because of its enhanced electrical and electrochemical properties. The manufacturing of three-dimensional (3D) structures of functionalized graphene-based materials, exhibiting geometric advantages to improve performance, allows the extension of their application fields. Herein, we demonstrate a practical 3D printing approach to fabricate silver nanoparticle (AgNP)-decorated graphene (AgNP-graphene) 3D microarchitectures. The approach consists of sequential processes: (i) direct-ink-writing (DIW) of graphene microarchitecture with ink including graphene flakes and silver nitrate (AgNO3), and (ii) chemical reduction of Ag ions with thermal treatment. AgNPs with a size distribution of 60 +/- 15.26 nm are decorated uniformly on the printed graphene objects, exhibiting a con-ductivity of similar to 4.78 S.cm(-1). Various AgNPs-graphene 3D microarchitectures are successfully printed, such as a Peano curve, Gosper curve, and volumetric structure of a five-pointed star polygon and butterfly. Potential electronic applications in flexible electronic devices, including resistance transducers for chloride ion (Cl-) sensors and 3D grids for electromagnetic interference (EMI) shielding, are demonstrated. This technique presents a facile approach for manufacturing AgNP-graphene 3D microarchitectures and has potential for applications in the field of advanced printed electronics.