Effect of ferroelectric poling on the photoelectrochemical activity of hematite-BaTiO3 nanowire arrays. (22nd October 2021)

• Record Type: Journal Article
• Authors: Sima, M.; Vasile, E.; Preda, N.; Sima, A.; Matei, E.; Logofatu, C.
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 73(2021)
• Page Start: 36232
• Page End: 36244
• Publication Date: 2021-10-22
• Subjects: Hematite nanowires -- Ferroelectric -- Water splitting -- Photoelectrochemical measurements; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.08.152
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Ferroelectric α-Fe2 O3 /BaTiO3 photoanodes (hematite/BT) were fabricated on FTO and FTO/TiO2 substrates using a hydrothermal process and spin coating along with thermal treatments. The prepared hematite nanowires had length under 1 μm and the BT film was about 18 nm thick. SEM, TEM and XPS investigations prove the formation of α-Fe2 O3 /BaTiO3 heterojunction structure. The ferroelectric poling of hematite/BT heterojunction was conducted both in propylene carbonate and in air. The photoelectrochemical performance of hematite/BT photoanodes is strongly influenced by the direction of ferroelectric polarization. The positive poling of the hematite/BT prepared on FTO/TiO2 substrate produces a 40.4% photocurrent density enhancement, in comparison with not poled version of the sample. Electrochemical impedance spectroscopy measurements provided usefull information regarding the effect of ferroelectric polarization on the charge transfer kinetics at the photoanode/electrolyte interface. Graphical abstract: Image 1 Highlights: Hematite/BaTiO3 heterostructures were prepared on FTO and FTO/TiO2 substrates. The formed photoanodes were poled in propylene carbonate and in air. The ferroelectric poling of the photoanodes modifies their photoactivity. FTO/hematite/BaTiO3 generates a higher photocurrent after negative poling. FTO/TiO2 /hematite/BaTiO3 shows a higher photocurrent after positive poling.