Study of Piezo-related and Photoelectrochemical Properties of Pristine Bi4Ti3O12 and Bi4Ti3O12-Reduced Graphene Oxide Nanocomposite Thin Films

Abstract

Bi4Ti3O12 films and Bi4Ti3O12/rGO composites on FTO substrates were fabricated using a facile sol-gel method and were investigated regarding its piezo-related capabilities photocatalysis and PEC properties UV-illumination and a hydrothermal approach were employed to reduce GO to rGO which was ascertained through XRD Raman and XPS The bonding between Bi4Ti3O12 and rGO was also ascertained through XPS because of the presence of the Ti-O-C peak on the samples of Bi4Ti3O12/rGO (UV) and Bi4Ti3O12/rGO (hydro) The piezo-related studies of the pristine Bi4Ti3O12 Bi4Ti3O12/rGO (UV) and Bi4Ti3O12/rGO (hydro) indicated minor piezotronic and piezophototronic effects which was attributed to poor inducement of piezopotential because of random distribution of Bi4Ti3O12 crystals instead of well aligned morphology However the photocatalytic and piezophotocatalytic properties of the samples were promising wherein Bi4Ti3O12/rGO (hydro) sample exhibited the best performance with k of approximately 24 ? 10-3/min-1 which was 4~5 times higher than that of the pristine Bi4Ti3O12 In addition the excellent photoelectrochemical performance of composite samples was preliminarily determined from the observation of an enhancement in its photocurrent density under visible light illumination The photocatalytic properties were consistent with the deduced energy band diagram which showed that a more negative conduction band positions than the formation potential of superoxide radicals (O2/‧O2-) was ideal for photodegradation applications and that the conduction and valence band edge potentials straddled the hydrogen and oxygen redox potentials was excellent for overall photoelectrochemical water splitting

Date of Award	2018 Aug 29
Original language	English
Supervisor	Kao-Shuo Chang (Supervisor)