Nanostructured N-doped Ti3C2/TiO2 composite for high-performance supercapacitor

Herein, the N-doped Ti 3 C 2 /TiO 2 nanostructure has been synthesized via hydrothermal treatment and following annealing in NH 3 . TiO 2 nanoparticles in-situ grow on the surface of Ti 3 C 2 spontaneously, resulting in the stable electron transport between TiO 2 and Ti 3 C 2 . Besides, Ti 3 C 2 nanosheets as conductive substrates make up for the poor conductivity of TiO 2 . The doping of N in Ti 3 C 2 /TiO 2 composite further improves the electrical conduction. The ultimate N-doped Ti 3 C 2 /TiO 2 composite achieves a higher specific capacitance of 737.4 F g −1 than Ti 3 C 2 (324.4 F g −1 ) at 0.5 A g −1 . More importantly, the composite displays a high specific capacitance retention of 81 % over 12,000 cycles. Besides, the assembled symmetrical supercapacitor (SSC) manifests an excellent specific capacitance of 236.4 F g −1 at 1 A g −1 and a comparable energy density of 32.8 Wh kg −1 at the power density of 500 W kg −1 . This work provides promising guidance for the fabrication of durable electrodes for energy storage application.