Compact hematite buffer layer as a promoter of nanorod photoanode performances.

R Milan,I Concina,N Comisso,K Kaunisto,N V Tkachenko,C Baratto,S Cattarin

doi:10.1038/srep35049

Abstract

The effect of a thin α-Fe2O3 compact buffer layer (BL) on the photoelectrochemical performances of a bare α-Fe2O3 nanorods photoanode is investigated. The BL is prepared through a simple spray deposition onto a fluorine-doped tin oxide (FTO) conducting glass substrate before the growth of a α-Fe2O3 nanorods via a hydrothermal process. Insertion of the hematite BL between the FTO and the nanorods markedly enhances the generated photocurrent, by limiting undesired losses of photogenerated charges at the FTO||electrolyte interface. The proposed approach warrants a marked improvement of material performances, with no additional thermal treatment and no use/dispersion of rare or toxic species, in agreement with the principles of green chemistry.

Highlights

Bard and Hardee[1] demonstrated some decades ago the potential hold by hematite (α-phase of iron oxide) as a suitable material for photoelectrochemical water oxidation
Hematite NRs are expected to present some deviation from a perfect vertical alignment with respect to the glass substrate due to the shape of fluorine-doped tin oxide (FTO) crystallites and thinness of the hematite buffer layer (BL) atop as well as a reduced compactness in correspondence with FTO underlying grains
It is worth noting that FTO appearance is not modified by the spray deposition of hematite BL, which is constituted by very small particles

Summary

Introduction

Bard and Hardee[1] demonstrated some decades ago the potential hold by hematite (α-phase of iron oxide) as a suitable material for photoelectrochemical water oxidation. The use of hematite as BL eliminates any chance of self-doping, ensuring that observed performance enhancement is exclusively due to the reduction of charge losses at the FTO||electrolyte interface, which is a critical step in view of the fabrication of efficient photoelectrodes for PECs. Results and Discussion

Results

Conclusion