Construction of N, S-co-doped graphene/polyaniline composite as free-standing electrode material

Summary Herein, N, S-co-doped graphene hydrogel (N/SGH) was first prepared by one-pot feasible hydrothermal approach using thiourea as a dopant for both N and S sources. And then, polyaniline (PANI) was grown on the surface of N, S-co-doped graphene hydrogel via simple adsorption of aniline monomer and in situ polymerization process. The N, S-co-doped graphene/polyaniline (N/SGH/PANI) composite hydrogel was fabricated as a free-standing and binder-free electrode material. Due to the co-doped synergistic effect, the N/SGH electrode exhibited enhanced electrochemical performances. The N/SGH electrode displays a specific capacitance of 130.4 F/g at 0.5 A/g. Compared with pure graphene hydrogel (GH), the specific capacitance of N/SGH and N-doped graphene (NGH) electrodes at 0.5 A/g increased by 53% and 20%, respectively. PANI pseudocapacitor material was introduced to further improve its capacitive performance. The resultant N/SGH/PANI composite electrode could achieve a max specific capacitance of 236.5 F/g at 0.5 A/g. In addition, N/SGH/PANI composite electrode showed stable cycle performance with the capacity retention of 95.1% after 1000 cycles performed at 10 A/g. Those provide a fabrication strategy for the design of high-performance supercapacitors electrode materials.