One-step hydrothermal synthesis of Nb doped brookite TiO2 nanosheets with enhanced lithium-ion intercalation properties

Abstract

In the present work, Nb doped brookite TiO₂ nanosheets were successfully synthesized via a one-step hydrothermal route. The synthesized samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning and transmission electron microscopy (SEM/TEM) and X-ray photoelectron spectroscopy (XPS). According to the experimental results, a possible mechanism for the formation of Nb doped brookite TiO₂ nanosheets was proposed. Furthermore, Nb doped brookite TiO₂ nanosheets were used as an anode material for the Li-ion intercalation reaction and it was found that their electronic/ionic conductivity was improved. At the same time, the cell made of Nb doped brookite TiO₂ nanosheets also exhibited enhanced lithium-ion intercalation properties. For instance, this material displayed reversible capacities of 119.7 and 104.6 mA h g⁻¹ at 5 C after 100 and 500 cycles, respectively.