Compósitos poliméricos de PVA/PVDF/Li e cerâmico de Bi0,5Na0,5Ba(TiO3)2 com alto potencial em aplicações energéticas

Abstract

This work presents an approach to polymeric and ceramic composites with high potential for use in energy applications. It consists of a study on polymeric composites of poly (vinyl alcohol)/poly (vinylidene fluoride) PVA/PVDF doped with lithium for possible applications as solid electrolytes and ceramic composites in the form of thin films of Bi 0.5 Na 0.5 Ba (TiO 3 2 for electrocatalytic applications aimed at the degradation of organic ciprofloxacin molecules. A study is carried out on the electrical, thermal, morphological, electrocatalytic and structural properties using the techniques of X ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Complex Impedance Spectroscopy (EIC), Raman spectroscopy and Atomic Force Microscopy (AFM). It was possible to verify that the increase in PVA content in the PVA/PVDF/Li composite favors the reduction of electrical resistance. XRD revealed that there was the formation of PVA and the α and β phases of PVDF with characteristic peaks of PVDF centered at 2θ = 18.3°, 2θ =19.9°, 2θ = 38,4° and PVA at 2θ = 19.6° and 22.3°. FTIR confirmed the coexistence of the α PVDF and β PVDF phases. EIC revealed a reduction in electrical resistance with increasing PVA content. The sample with 75%PVA25%PVDF1% Li presented the lowest value (1.3 x 10 5 Ω) of electrical resistance. For electrocatalytic applications, XRD revealed that the annealed BNT BT thin films showed a preferential light (001) orientation, and the crystallite sizes increased with annealing temperature from 14.76 to 27.88 nm and that the electrodes fabricated with our BNT BT thin films revealed excellent electrocatalytic performance. However, the total degradation of ciprofloxacin molecules was observed only for the electrode obtained at 600ºC after 60 min of electrolysis, which is attributed to a combination of structural and morphological properties that act together to enhance electrocatalytic activity. The results revealed that polymer and ceramic composites are potential materials for use in energy applications.