Pseudocapacitive performance of binder-free nanostructured TT-Nb₂O₅/FTO electrode in aqueous electrolyte

TT-Nb₂O₅ nanoparticles grown on electrically conducting fluorine-doped tin oxide (FTO) glass were successfully synthesized by a facile one-pot hydrothermal method at low temperature. The as-prepared nanostructured TT-Nb₂O₅/FTO was directly used as the working electrode to investigate its pseudocapacitive performance without any binder or conductive agent, which exhibited a high specific capacitance of 322 F g^-1 at a current density of 3.68 A g^-1, excellent rate capability (258.1 F g^-1 at a high scan rate of 100 mV s^-1 is about 91.6% of that at 5 mV s^-1), and good cycling stability (the capacitance retention is 74.3% after 3000 cycles). More importantly, it is the first time electrochemical measurements for Nb₂O₅ electrode in aqueous electrolyte, which are low-cost and easy to operate, have been carried out.