Preparation and Characterization of Nanocrystal V_2O_5

摘要

Nanocrystal V_2O_5 with granular shape and of various sizes was prepared by oxidative pyrolysis of the single molecular precursor, (NH_4)_5[(VO)_6(CO_3)_4(OH)_9]·10H_2O, at < = 630 deg C in a flow of air or oxygen gas. The thermolysis process of the precursor was investigated by TGA/DTGA and DTA in a flow of air. The data of the DTA curve indicate that fine particles of V_2O_5 are easier to crystallize and have a lower melting point. The IR spectra of various size V_2O_5 show that the absorption wavenumbers of the bands decreased gradually and the absorption at 494 approx 518 cm~(-1) disappeared gradually as the powder sizes decreased, which is attributed to size effect.