Synthesis and characterization of Nb2O5@C core-shell nanorods and Nb2O5 nanorods by reacting Nb(OEt)5 via RAPET (reaction under autogenic pressure at elevated temperatures) technique

The reaction of pentaethoxy niobate, Nb(OEt)(5), at elevated temperature (800 degrees C) under autogenic pressure provides a chemical route to niobium oxide nanorods coated with amorphous carbon. This synthetic approach yielded nanocrystalline particles of Nb2O5@C. As prepared Nb2O5@C core-shell nanorods is annealed under air at 500 degrees C for 3 h ( removing the carbon coating) results in neat Nb2O5 nanorods. According to the TEM measurements, the Nb2O5 crystals exhibit particle sizes between 25 nm and 100 nm, and the Nb2O5 crystals display rod-like shapes without any indication of an amorphous character. The optical band gap of the Nb2O5 nanorods was determined by diffuse reflectance spectroscopy (DRS) and was found to be 3.8 eV.