Issue 1, 2017

Gradient doping of phosphorus in Fe2O3 nanoarray photoanodes for enhanced charge separation

Abstract

Hematite (α-Fe2O3) is a promising candidate for solar-to-hydrogen energy conversion. However, the low carrier mobility and extremely high charge recombination rate limit the practical application of hematite in solar water splitting. This paper describes the fabrication of a Fe2O3 photoanode with gradient incorporation of phosphorus (P) employing a facile dipping and annealing method to improve the charge separation for enhanced photoelectrochemical water oxidation. This gradient P incorporation increases the width of band bending over a large region in Fe2O3, which is crucial for promoting the charge separation efficiency in the bulk. Although both gradient and homogeneous P-incorporated Fe2O3 samples exhibit similar electrical conductivity, the Fe2O3 electrode with a gradient P concentration presents an additional charge separation effect. A photocurrent of ∼1.48 mA cm−2 is obtained at 1.23 V vs. reversible hydrogen electrode (vs. RHE) under air mass 1.5G illumination. Additionally, the H2O oxidation kinetics of Fe2O3 with gradient P incorporation was further improved upon loading cobalt phosphate as cocatalyst, reaching a photocurrent of ∼2.0 mA cm−2 at 1.23 V vs. RHE.

Graphical abstract: Gradient doping of phosphorus in Fe2O3 nanoarray photoanodes for enhanced charge separation

Supplementary files

Article information

Article type
Edge Article
Submitted
18 Ago 2016
Accepted
02 Okt 2016
First published
03 Okt 2016
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2017,8, 91-100

Gradient doping of phosphorus in Fe2O3 nanoarray photoanodes for enhanced charge separation

Z. Luo, C. Li, S. Liu, T. Wang and J. Gong, Chem. Sci., 2017, 8, 91 DOI: 10.1039/C6SC03707K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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