Hydrothermal fabrication and study of delafossite (CuFeO2) thin films on fluorine doped tin oxide substrates

Abstract

CuFeO2 is a suitable photocatalytic material owing to its narrow band gap in the visible light region Moreover CuFeO2 also has a suitable band positions as a photocathode for photoelectrochemical (PEC) water splitting However few studies have focused on fabricating CuFeO2 thin films by a hydrothermal method and the associated physical and chemical properties are still yet to be extensively studied From the literature CuFeO2 powders were synthesized in highly basic conditions by hydrothermal methods however the condition was not suitable for fabricating CuFeO2 thin films on transparent conducting substrates In the current study CuFeO2 thin films were successfully fabricated on the fluorine doped tin oxide (FTO) substrates with the assistance of a seed layer which was tailored by tuning various deposition parameters The XRD and SEM results showed the growth of CuFeO2 films on FTO substrates The SEM images also ascertained the morphology and uniformity of CuFeO2 films The XPS was used to determine the constituent elements and chemical states of CuFeO2 The UPS and UV-vis were used to investigate the optical property and band structure of CuFeO2 films In addition the photocatalytic activities of CuFeO2 films were studied including photodegradation of methylene blue dye and PEC water splitting The CuFeO2 films based on drop casting seed layers exhibited the photodegradation rate constant k of approximately 6 7*10-3/min The associated photocurrent density was enhanced under illumination and the measured applied bias photon-to-current conversion efficiency (ABPE) was approximately 0 501 % at applied bias at -0 75 V

Date of Award	2019
Original language	English
Supervisor	Kao-Shuo Chang (Supervisor)