Propriedades eletrônicas, óticas e estruturais do filme semicondutor híbrido poliidroxibutirato/polietilenoglicol/ferro

Abstract

In this work, the polyhydroxybutyrate (PHB) films with polyethyleneglycol (PEG) were prepared using the solvent evaporation technique (casting). The hybrid materials were obtained by deposition / dispersion of iron (Fe0 ) over pure PHB film using an RF source and DC Sputtering with a power of 50 Watts, for application in electric and photocatalytic devices. The hybrids were characterized by Diffractometry X-ray (DRX), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and the Band Gap was measured by Shimadzu spectrophotometer coupled with a diffuse reflectance detector. The electrical measurements of capacitance, resistance, impedance and inductance were held in an LCR measurer. The Xray diffraction for PHB and the hybrid PHB/PEG/Fe showed no shift in the peaks, only a lower intensity was observed. The DSC showed that the iron influence caused the decrease of the biopolymer melting temperature of PHB/PEG/Fe. No changes or appearance of new bands was identified by infrared which is probably due to the small amount of iron used in the deposition. By means of the spectra analysis can be said that there was no iron interaction with the PHB using iron deposition technique by sputtering. The PHB/PEG showed a band gap of 4.14 eV, characteristic of an almost insulating. Differently, the hybrid PHB/PEG/Fe showed a smaller gap band 2.63 eV characteristic of a semiconductor. The decrease of band gap may facilitate treatment in the transition of electrons between the valence bands are required, such as the Fenton process and Photocatalysis and application of the hybrid material devices. The photocatalytic test hybrid PHB/PEG/Fe had a higher color removal compared to PHB/PEG using ultraviolet light (UV) and the electrical tests confirm the production of a semiconductor hybrid polymer.