Determination of photon-driven charge transfer efficiency: drawbacks, accuracy and precision of different methods using Hematite as case of study
File(s)
Author(s)
Bedoya-Lora, Franky E
Valencia-García, Michael E
Hankin, Anna
Klotz, Dino
Calderón, Jorge A
Type
Journal Article
Abstract
The electrochemical properties of photoelectrodes must be measured accurately and precisely to enable better comparisons between different materials. Along with the flat band potential, the interfacial charge transfer efficiency, which is the ratio between charge transfer rate at the photoelectrode surface and rate of charge carrier generation in the photoelectrode, can be used to predict the current density response at a given photon flux and electrode potential. The most widely used techniques for measuring charge transfer efficiencies are Photo-Electrochemical Impedance Spectroscopy (PEIS), current density ratios in the presence and absence of hole/electron scavengers, chrono-amperometry and Intensity Modulated Photocurrent Spectroscopy (IMPS). Charge transfer efficiencies can be estimated from PEIS and IMPS spectra either by using raw data (graphically), by fitting equivalent electrical circuits or by computing the Distribution of Relaxation Times (DRT). However, these techniques have their own drawbacks and impracticalities, that require researchers to make a choice between measuring accurately or pragmatically. Hitherto, the theoretical and experimental details of these techniques have not been summarised collectively and comprehensively. Here, we report the benefits and drawbacks, the accuracy, precision and best experimental recommendations when employing different techniques for photon-driven charge transfer efficiency determination.
Date Issued
2022-01
Date Acceptance
2021-11-04
Citation
Electrochimica Acta, 2022, 402, pp.139559-139559
ISSN
0013-4686
Publisher
Elsevier BV
Start Page
139559
End Page
139559
Journal / Book Title
Electrochimica Acta
Volume
402
Copyright Statement
© 2021 Elsevier Ltd. All rights reserved.
Identifier
https://www.sciencedirect.com/science/article/pii/S0013468621018430
Subjects
Energy
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Publication Status
Published
Article Number
139559
Date Publish Online
2021-11-09