Temperature: a nonnegligible factor for the formation of a structurally stable, self-assembled reduced graphite oxide hydrogel

The three-dimensional (3D) architecture of reduced graphite oxide (rGO) hydrogels is of interest in applications such as supercapacitors, soft machines and regenerative medicine, etc. The structural stability of the rGO hydrogel is the foundation for these applications. However, little attention has been paid to this issue. Here, the structural and performance stabilities of rGO hydrogels prepared at different temperatures were investigated in detail. It was found that 40 degrees C was the most effective condition for the reduction of graphite oxide, as the reducibility of vitamin C was embodied successfully and the network of the rGO hydrogel was formed. The rGO hydrogel prepared at 40 degrees C showed the best structural stability with time, the lowest electrical resistance and the highest mechanical strength. These results provide guidance for the synthesis of structurally stable rGO hydrogels and their further applications in electrical devices.