One-Step Hydrothermal Synthesis of Nitrogen-Doped Reduced Graphene Oxide/Hausmannite Manganese Oxide for Symmetric and Asymmetric Pseudocapacitors

[Image: see text] In this paper, the pseudocapacitive performance of nitrogen-doped and undoped reduced graphene oxide/tetragonal hausmannite nanohybrids (N-rGO/Mn(3)O(4) and rGO/Mn(3)O(4)) synthesized using a one-pot hydrothermal method is reported. The nanohybrid electrode materials displayed exceptional electrochemical performance relative to their respective individual precursors (i.e., reduced graphene oxide (rGO), nitrogen-doped reduced graphene oxide (N-rGO), and tetragonal hausmannite (Mn(3)O(4))) for symmetric pseudocapacitors. Among the two nanohybrids, N-rGO/Mn(3)O(4) displayed greater performance with a high specific capacitance of 345 F g(–1) at a current density of 0.1 A g(–1), excellent specific energy of 12.0 Wh kg(–1) (0.1 A g(–1)), and a high power density of 22.5 kW kg(–1) (10.0 A g(–1)), while rGO/Mn(3)O(4) demonstrated a high specific capacitance of 264 F g(–1) (0.1 A g(–1)) with specific energy and power densities of 9.2 Wh kg(–1) (0.1 A g(–1)) and 23.6 kW kg(–1) (10.0 A g(–1)), respectively. Furthermore, the N-rGO/Mn(3)O(4) nanohybrid exhibited an impressive pseudocapacitive performance when fabricated in an asymmetric configuration, having a stable potential window of 2.0 V in 1.0 M Na(2)SO(4) electrolyte. The nanohybrid showed excellent specific energy and power densities of 34.6 Wh kg(–1) (0.1 A g(–1)) and 14.01 kW kg(–1) (10.0 A g(–1)), respectively. These promising results provide a good substance for developing novel carbon-based metal oxide electrode materials in pseudocapacitor applications.