Preparation and characterization of nanocrystal V2O5

Nanocrystal V2O5 with granular shape and of various sizes was prepared by oxidative pyrolysis of the single molecular precursor, (NH4)(5)[(VO)(6)(CO3)(4)(OH)(9)]. 10H(2)O, at less than or equal to 630 degreesC 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 V2O5 are easier to crystallize and have a lower melting point. The IR spectra of various size V2O5 show that the absorption wavenumbers of the bands decreased gradually and the absorption at 494 similar to 518 cm(-1) disappeared gradually as the powder sizes decreased, which is attributed to size effect. (C) 2001 Academic Press.