Obtenção de nanofibras de SnO2 dopadas com manganês.

Abstract

Tin oxide (SnO2) is a semiconductor metal oxide that has been extensively investigated and prepared in the form of nanofibers for application in photocatalysis, gas sensing, transparent electrodes for solar cells, among others. Thus, this work aimed to synthesize SnO2 nanofibers doped with manganese (Mn) (0, 1,5, 3,0, 5,0, 7,0 and 10,0 at.% Mn) using solution blow spinning technique (SBS) and to analyze the influence of Mn concentration on the thermal, morphological, structural and electrical properties of the nanofibres produced. Hybrid nanofibers were successfully obtained using a solution consisting of ethanol/N,N-dimethylformamide (DMF), poly (vinyl pyrrolidone) (PVP), manganese acetate and tin chloride dihydrate, which were subjected to calcination at 700 ºC to convert the precursors in SnO2 phase with and without dopant. The nanofibers were characterized in terms of their thermal behavior, morphology, chemical composition, and structural and electrical properties. The obtained fibers presented tubular (hollow) morphology and average diameters in the nanometer range. The SnO2 phase formation was confirmed for all samples and it was observed that Mn formed solid solution with SnO2. In addition, Mn caused a reduction in SnO2 lattice parameters and in crystallite size. Nanofibers of pure and Mn-doped SnO2 showed, in general, ohmic behavior in the current-voltage (I-V) curves and there was a trend of increasing electric current with increasing Mn content. The nanometric dimensions of the fibers obtained in this work, together with Mn doping, their tubular morphology and the ohmic behavior observed in the I-V curves of all samples are promising characteristics for application in the gas sensing.