Tuning Electrical Conductivity and Surface Area of Chemically-Exfoliated Graphene Through Nanocrystal Functionalization

Silver nanocrystals were used to prevent the stacking of exfoliated graphene and to improve its conductivity. They were deposited onto chemically-exfoliated graphene through self-assembly and subsequent reduction of silver ions. Characterization by X-ray diffraction and transmission electron microscopy has confirmed the formation of silver/graphene hybrid. The nitrogen adsorption/desorption tests indicated that the nanoparticles inhibited the restacking of these sheets, resulting in larger active surface areas. The electrical conductivity of silver-deposited graphene was increased by nearly 3 times. The hybrid material was also used as an electrode of a supercapacitor and the capacitance of 326 F g−1 was achieved at a scan rate of 2 mV s−1. In contrast, as-produced chemically-exfoliated graphene based supercapacitors exhibited a capacitance of 109 F g−1. These results provide a valuable guidance for tuning the properties of chemically-exfoliated graphene in potential applications.