Gold Nanoparticles Supported on Nb2O5 for Low-Temperature CO Oxidation and as Cathode Materials for Li-ion Batteries

We prepared a series of Nb2O5 polymorphs by the sol-gel method and the sol-gel hydrothermal method. Gold nanoparticles supported on Nb2O5 were prepared by solid grinding method. Au on pseudohexagonal (TT-phase) Nb2O5 containing an amorphous phase exhibited higher catalytic activity for CO oxidation than did other Au/Nb2O5 polymorphs. For the electrochemical properties for cathode materials of Li-ion batteries, Nb2O5 (TT) exhibited high capacity of 208 mA h g(-1), and the deposition of Au onto Nb2O5 (TT) improved the capacity to 232 mA h g(-1). Capacity and CO oxidation activity were related; the higher the catalytic activity Au/Nb2O5 shows, the higher is the discharging capacity. From the characterization results, Nb2O5 (TT) contains oxygen vacancies (Nb4+ sites), and the oxygen vacancies of Nb2O5 (TT) would play an important role for CO oxidation and the performance for Li-ion batteries.