Dual absorber Fe2O3/WO3 host-guest architectures for improved charge generation and transfer in photoelectrochemical applications. (30th January 2017)

• Record Type: Journal Article
• Authors: Müller, Alexander; Kondofersky, Ilina; Folger, Alena; Fattakhova-Rohlfing, Dina; Bein, Thomas; Scheu, Christina
• Is Part Of: Materials research express. Volume 4:Number 1(2017)
• Publication Date: 2017-01-30
• Subjects: photoelectrochemical water splitting -- WO3 -- Fe2O3 -- dual absorber -- oxide heterostructure -- photoanodes -- host-guest architecture; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aa570f
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: In this study the influence of the spatial distribution and of different nanostructures of WO3 and Fe2 O3 in the dual absorber system Fe2 O3 /WO3 was systematically investigated for the first time. WO3 was applied as a scaffold and/or as a surface treatment to mesoporous Fe2 O3 films. Both approaches strongly increased the performance compared to the individual photoabsorbers. By combining a host guest architecture with a surface treatment, current densities of about 0.7 mA cm −2 at 1.23 V versus reversible hydrogen electrode under AM 1.5 illumination with an incident photon-to-current efficiency of 17% at 350 nm were achieved without the use of further catalysts. We could identify several beneficial interactions between Fe2 O3 and WO3 . WO3 strongly scatters visible light, resulting in increased absorption by Fe2 O3 and higher current densities. We also determined a cathodic shift in the onset potential to 0.8 V and increased transfer rates of up to 88%. This combination of beneficial effects proves the viability of the presented device architecture.