Comment on “Flat band potential determination: avoiding the pitfalls” by A. Hankin, F. E. Bedoya-Lora, J. C. Alexander, A. Regoutz and G. H. Kelsall, J. Mater. Chem. A, 2019, 7, 26162

Abstract

In this comment, it is shown that the work published by Hankin et al. [Hankin et al., J. Mater. Chem. A, 2019, 7, 26162–26176], while mostly timely and appropriate, present two mistakes that are discussed in detail. First, the determination of flat band potentials through a Mott–Schottky analysis is in principle not affected by the existence of a real surface area substantially larger than the geometric surface area and, second, the Gärtnet–Butler model may not be applicable for electrodes with high values of the absorption coefficient and low dopant density values.