OBTENÇÃO DE FASE ÚNICA DE PENTÓXIDO DE NIÓBIO POR UMA ROTA SIMPLES E SUA CARACTERIZAÇÃO

Brazil has the world’s largest reserve of niobium (~98%) which turns niobium compounds into extremely interesting materials from a strategic point of view in the country. Niobium pentoxide is an n-type semiconductor that presents interesting physical and mechanical properties. The presence of polymorphic phases on Nb2O5 powders has several implications from the scientific and application point of view. It is known that the H-phase is thermodynamically stable and can be obtained easily from amorphous Nb2O5 after heat treatment. In this work, niobic acid (Nb2O5.nH2O) produced by the Brazilian company CBMM has been used as the starting material to grow unique monoclinic P2 space group H-Nb2O5 crystals through a simple calcination route. The obtained material has been characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy) and micro-Raman and submitted to cyclic voltammetry measurements. The characterization results confirm that H-Nb2O5 crystallized in the monoclinic P2 space group.