Sodium Sulfate Template-Directed Methodology of Rolling Up a Two-Dimensional Graphene Nanosheet into a One-Dimensional Nanoscroll and Its Anode Performance in a Lithium-Ion Battery

Graphene nanoscroll has received enormous interest due to its potential applications in various fields. However, in practice there still remains a challenge toward cost-efficiency and scale-up production with the existing advanced experimental techniques. Herein, we report an integration methodology to construct a one-dimensional graphene nanoscroll (1D-GNS) from a two-dimensional graphene nanosheet (2D-rGO) via an ingenious template-directed synthesis approach, in which Na2SO4 was used as a sacrificial template for the first time. Na2SO4 was first generated on the surface of reduced graphene oxide (rGO) nanosheets by a combination of antisolvent self-assembly and heat treatment under moderate temperature, in sequence, to shape and maintain the 2D-rGO architecture into an rGO@Na2SO4 composite, which was then immediately quenched into water to dissolve the Na2SO4 template and meanwhile roll up the 2D graphene nanosheets into 1D nanoscrolls spontaneously, followed by a final thermal reduction to reduce the oxygenous groups. The crimping behavior of the 1D-GNS can be conducted by varying the heat-treatment temperature during the quenching process. The as-synthesized 1D-GNS gives quite good electrochemical stability when evaluated as an anode material in a Li-ion battery. This interesting methodology provides an avenue to design and fabricate other scroll-structured nanoarchitectures.