Synthesis of Nb2O5 Nanoplates and their Conversion into NbO2F Nanoparticles by Controlled Fluorination with Molecular Fluorine

Following a synthesis protocol developed by us, nanoparticles of NbO 2 F were prepared for the very first time by the gas‐solid type fluorination of hexagonal‐shaped niobium pentoxide (Nb 2 O 5 ) nanostructures with molecular fluorine (F 2 ). The optimized fluorination parameters, like F 2 pressure, gas‐solid reaction temperature, and duration, were very crucial for successful synthesis of the desired NbO 2 F nanomaterial. The hexagonal‐shaped Nb 2 O 5 nanoplates were synthesized in a previous step by a hydrothermal method. The oxide to oxyfluoride transformation protocol is highly efficient, giving single‐phase NbO 2 F in the cubic crystal system, as confirmed by powder X‐ray diffraction (XRD) and energy dispersive X‐ray spectroscopy (EDX). The structures of Nb 2 O 5 nanoplates and NbO 2 F nanoparticles were also characterized by vibrational spectroscopy (FTIR and Raman scattering). The morphologies of the materials were studied by transmission and scanning electron microscopy (T/SEM), which revealed that the hexagonal‐shaped plates of Nb 2 O 5 disintegrated into nanoparticles with an approximate size of 27 nm upon fluorination to provide NbO 2 F. The lithiation and sodiation ability of nanostructured NbO 2 F is established with relevant electrochemical properties.