Imperial College London

DrFrankyBedoya Lora

Faculty of EngineeringDepartment of Chemical Engineering

 
 
 
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Contact

 

f.bedoya-lora13 Website

 
 
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Location

 

B432Bone BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Bedoya-Lora:2017:10.1016/j.electacta.2017.08.090,
author = {Bedoya-Lora, FE and Hankin, A and Holmes-Gentle, I and Regoutz, A and Nania, M and Payne, DJ and Cabral, JT and Kelsall, GH},
doi = {10.1016/j.electacta.2017.08.090},
journal = {Electrochimica Acta},
pages = {1--11},
title = {Effects of low temperature annealing on the photo-electrochemical performance o tin-doped hematite photo-anodes},
url = {http://dx.doi.org/10.1016/j.electacta.2017.08.090},
volume = {251},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - The effects of post-deposition annealing at 400 and 500 °C on the photo-electrochemical performance of SnIV-doped α-Fe2O3 photo-anodes are reported. Samples were fabricated by spray pyrolysis on fluorine-doped tin oxide (FTO) and on titanium substrates. Photo-electrochemical, morphological and optical properties were determined to explain the shift in photocurrent densities to lower electrode potentials and the decrease of maximum photocurrent densities for alkaline water oxidation after annealing. Annealing at 400 and 500 °C in air did not affect significantly the morphology, crystallinity, optical absorption or spatial distributions of oxygen vacancy concentrations. However, XPS data showed a redistribution of SnIV near SnIV-doped α-Fe2O3 | 1 M NaOH interfaces after annealing. Thus, electron-hole recombination rates at photo-anode surfaces decreased after annealing, shifting photocurrents to lower electrode potentials. Conversely, depletion of SnIV in the α-Fe2O3 bulk could increase recombination rates therein and decrease photon absorption near 550 nm, due to an increased dopant concentration in the semiconductor depletion layer. This accounted for the decrease of maximum photocurrents when electron-hole recombination rates were suppressed using HO2− ions as a hole scavenger. The flat band potential of SnIV-doped α-Fe2O3 remained relatively constant at ca. 0.7 V vs. RHE, irrespective of annealing conditions.
AU - Bedoya-Lora,FE
AU - Hankin,A
AU - Holmes-Gentle,I
AU - Regoutz,A
AU - Nania,M
AU - Payne,DJ
AU - Cabral,JT
AU - Kelsall,GH
DO - 10.1016/j.electacta.2017.08.090
EP - 11
PY - 2017///
SN - 0013-4686
SP - 1
TI - Effects of low temperature annealing on the photo-electrochemical performance o tin-doped hematite photo-anodes
T2 - Electrochimica Acta
UR - http://dx.doi.org/10.1016/j.electacta.2017.08.090
UR - http://hdl.handle.net/10044/1/50431
VL - 251
ER -